| /* | 
 |  * Copyright (c) 2017, Alliance for Open Media. All rights reserved | 
 |  * | 
 |  * This source code is subject to the terms of the BSD 2 Clause License and | 
 |  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License | 
 |  * was not distributed with this source code in the LICENSE file, you can | 
 |  * obtain it at www.aomedia.org/license/software. If the Alliance for Open | 
 |  * Media Patent License 1.0 was not distributed with this source code in the | 
 |  * PATENTS file, you can obtain it at www.aomedia.org/license/patent. | 
 |  */ | 
 |  | 
 | #include <assert.h> | 
 |  | 
 | #include "config/aom_config.h" | 
 | #include "config/aom_scale_rtcd.h" | 
 |  | 
 | #include "aom/aom_codec.h" | 
 | #include "aom_dsp/bitreader_buffer.h" | 
 | #include "aom_ports/mem_ops.h" | 
 |  | 
 | #include "av1/common/common.h" | 
 | #include "av1/common/obu_util.h" | 
 | #include "av1/common/timing.h" | 
 | #include "av1/decoder/decoder.h" | 
 | #include "av1/decoder/decodeframe.h" | 
 | #include "av1/decoder/obu.h" | 
 |  | 
 | aom_codec_err_t aom_get_num_layers_from_operating_point_idc( | 
 |     int operating_point_idc, unsigned int *number_spatial_layers, | 
 |     unsigned int *number_temporal_layers) { | 
 |   // derive number of spatial/temporal layers from operating_point_idc | 
 |  | 
 |   if (!number_spatial_layers || !number_temporal_layers) | 
 |     return AOM_CODEC_INVALID_PARAM; | 
 |  | 
 |   if (operating_point_idc == 0) { | 
 |     *number_temporal_layers = 1; | 
 |     *number_spatial_layers = 1; | 
 |   } else { | 
 |     *number_spatial_layers = 0; | 
 |     *number_temporal_layers = 0; | 
 |     for (int j = 0; j < MAX_NUM_SPATIAL_LAYERS; j++) { | 
 |       *number_spatial_layers += | 
 |           (operating_point_idc >> (j + MAX_NUM_TEMPORAL_LAYERS)) & 0x1; | 
 |     } | 
 |     for (int j = 0; j < MAX_NUM_TEMPORAL_LAYERS; j++) { | 
 |       *number_temporal_layers += (operating_point_idc >> j) & 0x1; | 
 |     } | 
 |   } | 
 |  | 
 |   return AOM_CODEC_OK; | 
 | } | 
 |  | 
 | static int is_obu_in_current_operating_point(AV1Decoder *pbi, | 
 |                                              const ObuHeader *obu_header) { | 
 |   if (!pbi->current_operating_point || !obu_header->has_extension) { | 
 |     return 1; | 
 |   } | 
 |  | 
 |   if ((pbi->current_operating_point >> obu_header->temporal_layer_id) & 0x1 && | 
 |       (pbi->current_operating_point >> (obu_header->spatial_layer_id + 8)) & | 
 |           0x1) { | 
 |     return 1; | 
 |   } | 
 |   return 0; | 
 | } | 
 |  | 
 | static int byte_alignment(AV1_COMMON *const cm, | 
 |                           struct aom_read_bit_buffer *const rb) { | 
 |   while (rb->bit_offset & 7) { | 
 |     if (aom_rb_read_bit(rb)) { | 
 |       cm->error->error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return -1; | 
 |     } | 
 |   } | 
 |   return 0; | 
 | } | 
 |  | 
 | static uint32_t read_temporal_delimiter_obu() { return 0; } | 
 |  | 
 | // Returns a boolean that indicates success. | 
 | static int read_bitstream_level(AV1_LEVEL *seq_level_idx, | 
 |                                 struct aom_read_bit_buffer *rb) { | 
 |   *seq_level_idx = aom_rb_read_literal(rb, LEVEL_BITS); | 
 |   if (!is_valid_seq_level_idx(*seq_level_idx)) return 0; | 
 |   return 1; | 
 | } | 
 |  | 
 | // Returns whether two sequence headers are consistent with each other. | 
 | // Note that the 'op_params' field is not compared per Section 7.5 in the spec: | 
 | //   Within a particular coded video sequence, the contents of | 
 | //   sequence_header_obu must be bit-identical each time the sequence header | 
 | //   appears except for the contents of operating_parameters_info. | 
 | static int are_seq_headers_consistent(const SequenceHeader *seq_params_old, | 
 |                                       const SequenceHeader *seq_params_new) { | 
 |   return !memcmp(seq_params_old, seq_params_new, | 
 |                  offsetof(SequenceHeader, op_params)); | 
 | } | 
 |  | 
 | // On success, sets pbi->sequence_header_ready to 1 and returns the number of | 
 | // bytes read from 'rb'. | 
 | // On failure, sets pbi->common.error.error_code and returns 0. | 
 | static uint32_t read_sequence_header_obu(AV1Decoder *pbi, | 
 |                                          struct aom_read_bit_buffer *rb) { | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   const uint32_t saved_bit_offset = rb->bit_offset; | 
 |  | 
 |   // Verify rb has been configured to report errors. | 
 |   assert(rb->error_handler); | 
 |  | 
 |   // Use a local variable to store the information as we decode. At the end, | 
 |   // if no errors have occurred, cm->seq_params is updated. | 
 |   SequenceHeader sh = *cm->seq_params; | 
 |   SequenceHeader *const seq_params = &sh; | 
 |  | 
 |   seq_params->profile = av1_read_profile(rb); | 
 |   if (seq_params->profile > CONFIG_MAX_DECODE_PROFILE) { | 
 |     pbi->error.error_code = AOM_CODEC_UNSUP_BITSTREAM; | 
 |     return 0; | 
 |   } | 
 |  | 
 |   // Still picture or not | 
 |   seq_params->still_picture = aom_rb_read_bit(rb); | 
 |   seq_params->reduced_still_picture_hdr = aom_rb_read_bit(rb); | 
 |   // Video must have reduced_still_picture_hdr = 0 | 
 |   if (!seq_params->still_picture && seq_params->reduced_still_picture_hdr) { | 
 |     pbi->error.error_code = AOM_CODEC_UNSUP_BITSTREAM; | 
 |     return 0; | 
 |   } | 
 |  | 
 |   if (seq_params->reduced_still_picture_hdr) { | 
 |     seq_params->timing_info_present = 0; | 
 |     seq_params->decoder_model_info_present_flag = 0; | 
 |     seq_params->display_model_info_present_flag = 0; | 
 |     seq_params->operating_points_cnt_minus_1 = 0; | 
 |     seq_params->operating_point_idc[0] = 0; | 
 |     if (!read_bitstream_level(&seq_params->seq_level_idx[0], rb)) { | 
 |       pbi->error.error_code = AOM_CODEC_UNSUP_BITSTREAM; | 
 |       return 0; | 
 |     } | 
 |     seq_params->tier[0] = 0; | 
 |     seq_params->op_params[0].decoder_model_param_present_flag = 0; | 
 |     seq_params->op_params[0].display_model_param_present_flag = 0; | 
 |   } else { | 
 |     seq_params->timing_info_present = aom_rb_read_bit(rb); | 
 |     if (seq_params->timing_info_present) { | 
 |       av1_read_timing_info_header(&seq_params->timing_info, &pbi->error, rb); | 
 |  | 
 |       seq_params->decoder_model_info_present_flag = aom_rb_read_bit(rb); | 
 |       if (seq_params->decoder_model_info_present_flag) | 
 |         av1_read_decoder_model_info(&seq_params->decoder_model_info, rb); | 
 |     } else { | 
 |       seq_params->decoder_model_info_present_flag = 0; | 
 |     } | 
 |     seq_params->display_model_info_present_flag = aom_rb_read_bit(rb); | 
 |     seq_params->operating_points_cnt_minus_1 = | 
 |         aom_rb_read_literal(rb, OP_POINTS_CNT_MINUS_1_BITS); | 
 |     for (int i = 0; i < seq_params->operating_points_cnt_minus_1 + 1; i++) { | 
 |       seq_params->operating_point_idc[i] = | 
 |           aom_rb_read_literal(rb, OP_POINTS_IDC_BITS); | 
 |       if (!read_bitstream_level(&seq_params->seq_level_idx[i], rb)) { | 
 |         pbi->error.error_code = AOM_CODEC_UNSUP_BITSTREAM; | 
 |         return 0; | 
 |       } | 
 |       // This is the seq_level_idx[i] > 7 check in the spec. seq_level_idx 7 | 
 |       // is equivalent to level 3.3. | 
 |       if (seq_params->seq_level_idx[i] >= SEQ_LEVEL_4_0) | 
 |         seq_params->tier[i] = aom_rb_read_bit(rb); | 
 |       else | 
 |         seq_params->tier[i] = 0; | 
 |       if (seq_params->decoder_model_info_present_flag) { | 
 |         seq_params->op_params[i].decoder_model_param_present_flag = | 
 |             aom_rb_read_bit(rb); | 
 |         if (seq_params->op_params[i].decoder_model_param_present_flag) | 
 |           av1_read_op_parameters_info(&seq_params->op_params[i], | 
 |                                       seq_params->decoder_model_info | 
 |                                           .encoder_decoder_buffer_delay_length, | 
 |                                       rb); | 
 |       } else { | 
 |         seq_params->op_params[i].decoder_model_param_present_flag = 0; | 
 |       } | 
 |       if (seq_params->timing_info_present && | 
 |           (seq_params->timing_info.equal_picture_interval || | 
 |            seq_params->op_params[i].decoder_model_param_present_flag)) { | 
 |         seq_params->op_params[i].bitrate = av1_max_level_bitrate( | 
 |             seq_params->profile, seq_params->seq_level_idx[i], | 
 |             seq_params->tier[i]); | 
 |         // Level with seq_level_idx = 31 returns a high "dummy" bitrate to pass | 
 |         // the check | 
 |         if (seq_params->op_params[i].bitrate == 0) | 
 |           aom_internal_error(&pbi->error, AOM_CODEC_UNSUP_BITSTREAM, | 
 |                              "AV1 does not support this combination of " | 
 |                              "profile, level, and tier."); | 
 |         // Buffer size in bits/s is bitrate in bits/s * 1 s | 
 |         seq_params->op_params[i].buffer_size = seq_params->op_params[i].bitrate; | 
 |       } | 
 |       if (seq_params->timing_info_present && | 
 |           seq_params->timing_info.equal_picture_interval && | 
 |           !seq_params->op_params[i].decoder_model_param_present_flag) { | 
 |         // When the decoder_model_parameters are not sent for this op, set | 
 |         // the default ones that can be used with the resource availability mode | 
 |         seq_params->op_params[i].decoder_buffer_delay = 70000; | 
 |         seq_params->op_params[i].encoder_buffer_delay = 20000; | 
 |         seq_params->op_params[i].low_delay_mode_flag = 0; | 
 |       } | 
 |  | 
 |       if (seq_params->display_model_info_present_flag) { | 
 |         seq_params->op_params[i].display_model_param_present_flag = | 
 |             aom_rb_read_bit(rb); | 
 |         if (seq_params->op_params[i].display_model_param_present_flag) { | 
 |           seq_params->op_params[i].initial_display_delay = | 
 |               aom_rb_read_literal(rb, 4) + 1; | 
 |           if (seq_params->op_params[i].initial_display_delay > 10) | 
 |             aom_internal_error( | 
 |                 &pbi->error, AOM_CODEC_UNSUP_BITSTREAM, | 
 |                 "AV1 does not support more than 10 decoded frames delay"); | 
 |         } else { | 
 |           seq_params->op_params[i].initial_display_delay = 10; | 
 |         } | 
 |       } else { | 
 |         seq_params->op_params[i].display_model_param_present_flag = 0; | 
 |         seq_params->op_params[i].initial_display_delay = 10; | 
 |       } | 
 |     } | 
 |   } | 
 |   // This decoder supports all levels.  Choose operating point provided by | 
 |   // external means | 
 |   int operating_point = pbi->operating_point; | 
 |   if (operating_point < 0 || | 
 |       operating_point > seq_params->operating_points_cnt_minus_1) | 
 |     operating_point = 0; | 
 |   pbi->current_operating_point = | 
 |       seq_params->operating_point_idc[operating_point]; | 
 |   if (aom_get_num_layers_from_operating_point_idc( | 
 |           pbi->current_operating_point, &pbi->number_spatial_layers, | 
 |           &pbi->number_temporal_layers) != AOM_CODEC_OK) { | 
 |     pbi->error.error_code = AOM_CODEC_ERROR; | 
 |     return 0; | 
 |   } | 
 |  | 
 |   av1_read_sequence_header(cm, rb, seq_params); | 
 |  | 
 |   av1_read_color_config(rb, pbi->allow_lowbitdepth, seq_params, &pbi->error); | 
 |   if (!(seq_params->subsampling_x == 0 && seq_params->subsampling_y == 0) && | 
 |       !(seq_params->subsampling_x == 1 && seq_params->subsampling_y == 1) && | 
 |       !(seq_params->subsampling_x == 1 && seq_params->subsampling_y == 0)) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_UNSUP_BITSTREAM, | 
 |                        "Only 4:4:4, 4:2:2 and 4:2:0 are currently supported, " | 
 |                        "%d %d subsampling is not supported.\n", | 
 |                        seq_params->subsampling_x, seq_params->subsampling_y); | 
 |   } | 
 |  | 
 |   seq_params->film_grain_params_present = aom_rb_read_bit(rb); | 
 |  | 
 |   if (av1_check_trailing_bits(pbi, rb) != 0) { | 
 |     // pbi->error.error_code is already set. | 
 |     return 0; | 
 |   } | 
 |  | 
 |   // If a sequence header has been decoded before, we check if the new | 
 |   // one is consistent with the old one. | 
 |   if (pbi->sequence_header_ready) { | 
 |     if (!are_seq_headers_consistent(cm->seq_params, seq_params)) | 
 |       pbi->sequence_header_changed = 1; | 
 |   } | 
 |  | 
 |   *cm->seq_params = *seq_params; | 
 |   pbi->sequence_header_ready = 1; | 
 |  | 
 |   return ((rb->bit_offset - saved_bit_offset + 7) >> 3); | 
 | } | 
 |  | 
 | // On success, returns the frame header size. On failure, calls | 
 | // aom_internal_error and does not return. If show existing frame, | 
 | // also marks the data processing to end after the frame header. | 
 | static uint32_t read_frame_header_obu(AV1Decoder *pbi, | 
 |                                       struct aom_read_bit_buffer *rb, | 
 |                                       const uint8_t *data, | 
 |                                       const uint8_t **p_data_end, | 
 |                                       int trailing_bits_present) { | 
 |   const uint32_t hdr_size = | 
 |       av1_decode_frame_headers_and_setup(pbi, rb, trailing_bits_present); | 
 |   const AV1_COMMON *cm = &pbi->common; | 
 |   if (cm->show_existing_frame) { | 
 |     *p_data_end = data + hdr_size; | 
 |   } | 
 |   return hdr_size; | 
 | } | 
 |  | 
 | // On success, returns the tile group header size. On failure, calls | 
 | // aom_internal_error() and returns -1. | 
 | static int32_t read_tile_group_header(AV1Decoder *pbi, | 
 |                                       struct aom_read_bit_buffer *rb, | 
 |                                       int *start_tile, int *end_tile, | 
 |                                       int tile_start_implicit) { | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   CommonTileParams *const tiles = &cm->tiles; | 
 |   uint32_t saved_bit_offset = rb->bit_offset; | 
 |   int tile_start_and_end_present_flag = 0; | 
 |   const int num_tiles = tiles->rows * tiles->cols; | 
 |  | 
 |   if (!tiles->large_scale && num_tiles > 1) { | 
 |     tile_start_and_end_present_flag = aom_rb_read_bit(rb); | 
 |     if (tile_start_implicit && tile_start_and_end_present_flag) { | 
 |       aom_internal_error( | 
 |           &pbi->error, AOM_CODEC_UNSUP_BITSTREAM, | 
 |           "For OBU_FRAME type obu tile_start_and_end_present_flag must be 0"); | 
 |       return -1; | 
 |     } | 
 |   } | 
 |   if (tiles->large_scale || num_tiles == 1 || | 
 |       !tile_start_and_end_present_flag) { | 
 |     *start_tile = 0; | 
 |     *end_tile = num_tiles - 1; | 
 |   } else { | 
 |     int tile_bits = tiles->log2_rows + tiles->log2_cols; | 
 |     *start_tile = aom_rb_read_literal(rb, tile_bits); | 
 |     *end_tile = aom_rb_read_literal(rb, tile_bits); | 
 |   } | 
 |   if (*start_tile != pbi->next_start_tile) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "tg_start (%d) must be equal to %d", *start_tile, | 
 |                        pbi->next_start_tile); | 
 |     return -1; | 
 |   } | 
 |   if (*start_tile > *end_tile) { | 
 |     aom_internal_error( | 
 |         &pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |         "tg_end (%d) must be greater than or equal to tg_start (%d)", *end_tile, | 
 |         *start_tile); | 
 |     return -1; | 
 |   } | 
 |   if (*end_tile >= num_tiles) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "tg_end (%d) must be less than NumTiles (%d)", *end_tile, | 
 |                        num_tiles); | 
 |     return -1; | 
 |   } | 
 |   pbi->next_start_tile = (*end_tile == num_tiles - 1) ? 0 : *end_tile + 1; | 
 |  | 
 |   return ((rb->bit_offset - saved_bit_offset + 7) >> 3); | 
 | } | 
 |  | 
 | // On success, returns the tile group OBU size. On failure, sets | 
 | // pbi->common.error.error_code and returns 0. | 
 | static uint32_t read_one_tile_group_obu( | 
 |     AV1Decoder *pbi, struct aom_read_bit_buffer *rb, int is_first_tg, | 
 |     const uint8_t *data, const uint8_t *data_end, const uint8_t **p_data_end, | 
 |     int *is_last_tg, int tile_start_implicit) { | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   int start_tile, end_tile; | 
 |   int32_t header_size, tg_payload_size; | 
 |  | 
 |   assert((rb->bit_offset & 7) == 0); | 
 |   assert(rb->bit_buffer + aom_rb_bytes_read(rb) == data); | 
 |  | 
 |   header_size = read_tile_group_header(pbi, rb, &start_tile, &end_tile, | 
 |                                        tile_start_implicit); | 
 |   if (header_size == -1 || byte_alignment(cm, rb)) return 0; | 
 |   data += header_size; | 
 |   av1_decode_tg_tiles_and_wrapup(pbi, data, data_end, p_data_end, start_tile, | 
 |                                  end_tile, is_first_tg); | 
 |  | 
 |   tg_payload_size = (uint32_t)(*p_data_end - data); | 
 |  | 
 |   *is_last_tg = end_tile == cm->tiles.rows * cm->tiles.cols - 1; | 
 |   return header_size + tg_payload_size; | 
 | } | 
 |  | 
 | static void alloc_tile_list_buffer(AV1Decoder *pbi) { | 
 |   // The resolution of the output frame is read out from the bitstream. The data | 
 |   // are stored in the order of Y plane, U plane and V plane. As an example, for | 
 |   // image format 4:2:0, the output frame of U plane and V plane is 1/4 of the | 
 |   // output frame. | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   int tile_width, tile_height; | 
 |   av1_get_uniform_tile_size(cm, &tile_width, &tile_height); | 
 |   const int tile_width_in_pixels = tile_width * MI_SIZE; | 
 |   const int tile_height_in_pixels = tile_height * MI_SIZE; | 
 |   const int output_frame_width = | 
 |       (pbi->output_frame_width_in_tiles_minus_1 + 1) * tile_width_in_pixels; | 
 |   const int output_frame_height = | 
 |       (pbi->output_frame_height_in_tiles_minus_1 + 1) * tile_height_in_pixels; | 
 |   // The output frame is used to store the decoded tile list. The decoded tile | 
 |   // list has to fit into 1 output frame. | 
 |   assert((pbi->tile_count_minus_1 + 1) <= | 
 |          (pbi->output_frame_width_in_tiles_minus_1 + 1) * | 
 |              (pbi->output_frame_height_in_tiles_minus_1 + 1)); | 
 |  | 
 |   // Allocate the tile list output buffer. | 
 |   // Note: if cm->seq_params->use_highbitdepth is 1 and | 
 |   // cm->seq_params->bit_depth is 8, we could allocate less memory, namely, 8 | 
 |   // bits/pixel. | 
 |   if (aom_alloc_frame_buffer(&pbi->tile_list_outbuf, output_frame_width, | 
 |                              output_frame_height, cm->seq_params->subsampling_x, | 
 |                              cm->seq_params->subsampling_y, | 
 |                              (cm->seq_params->use_highbitdepth && | 
 |                               (cm->seq_params->bit_depth > AOM_BITS_8)), | 
 |                              0, cm->features.byte_alignment)) | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_MEM_ERROR, | 
 |                        "Failed to allocate the tile list output buffer"); | 
 | } | 
 |  | 
 | static void yv12_tile_copy(const YV12_BUFFER_CONFIG *src, int hstart1, | 
 |                            int hend1, int vstart1, int vend1, | 
 |                            YV12_BUFFER_CONFIG *dst, int hstart2, int vstart2, | 
 |                            int plane) { | 
 |   const int src_stride = (plane > 0) ? src->strides[1] : src->strides[0]; | 
 |   const int dst_stride = (plane > 0) ? dst->strides[1] : dst->strides[0]; | 
 |   int row, col; | 
 |  | 
 |   assert(src->flags & YV12_FLAG_HIGHBITDEPTH); | 
 |   assert(!(dst->flags & YV12_FLAG_HIGHBITDEPTH)); | 
 |  | 
 |   const uint16_t *src16 = | 
 |       CONVERT_TO_SHORTPTR(src->buffers[plane] + vstart1 * src_stride + hstart1); | 
 |   uint8_t *dst8 = dst->buffers[plane] + vstart2 * dst_stride + hstart2; | 
 |  | 
 |   for (row = vstart1; row < vend1; ++row) { | 
 |     for (col = 0; col < (hend1 - hstart1); ++col) *dst8++ = (uint8_t)(*src16++); | 
 |     src16 += src_stride - (hend1 - hstart1); | 
 |     dst8 += dst_stride - (hend1 - hstart1); | 
 |   } | 
 |   return; | 
 | } | 
 |  | 
 | static void copy_decoded_tile_to_tile_list_buffer(AV1Decoder *pbi, | 
 |                                                   int tile_idx) { | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   int tile_width, tile_height; | 
 |   av1_get_uniform_tile_size(cm, &tile_width, &tile_height); | 
 |   const int tile_width_in_pixels = tile_width * MI_SIZE; | 
 |   const int tile_height_in_pixels = tile_height * MI_SIZE; | 
 |   const int ssy = cm->seq_params->subsampling_y; | 
 |   const int ssx = cm->seq_params->subsampling_x; | 
 |   const int num_planes = av1_num_planes(cm); | 
 |  | 
 |   YV12_BUFFER_CONFIG *cur_frame = &cm->cur_frame->buf; | 
 |   const int tr = tile_idx / (pbi->output_frame_width_in_tiles_minus_1 + 1); | 
 |   const int tc = tile_idx % (pbi->output_frame_width_in_tiles_minus_1 + 1); | 
 |   int plane; | 
 |  | 
 |   // Copy decoded tile to the tile list output buffer. | 
 |   for (plane = 0; plane < num_planes; ++plane) { | 
 |     const int shift_x = plane > 0 ? ssx : 0; | 
 |     const int shift_y = plane > 0 ? ssy : 0; | 
 |     const int h = tile_height_in_pixels >> shift_y; | 
 |     const int w = tile_width_in_pixels >> shift_x; | 
 |  | 
 |     // src offset | 
 |     int vstart1 = pbi->dec_tile_row * h; | 
 |     int vend1 = vstart1 + h; | 
 |     int hstart1 = pbi->dec_tile_col * w; | 
 |     int hend1 = hstart1 + w; | 
 |     // dst offset | 
 |     int vstart2 = tr * h; | 
 |     int hstart2 = tc * w; | 
 |  | 
 |     if (cm->seq_params->use_highbitdepth && | 
 |         cm->seq_params->bit_depth == AOM_BITS_8) { | 
 |       yv12_tile_copy(cur_frame, hstart1, hend1, vstart1, vend1, | 
 |                      &pbi->tile_list_outbuf, hstart2, vstart2, plane); | 
 |     } else { | 
 |       switch (plane) { | 
 |         case 0: | 
 |           aom_yv12_partial_copy_y(cur_frame, hstart1, hend1, vstart1, vend1, | 
 |                                   &pbi->tile_list_outbuf, hstart2, vstart2); | 
 |           break; | 
 |         case 1: | 
 |           aom_yv12_partial_copy_u(cur_frame, hstart1, hend1, vstart1, vend1, | 
 |                                   &pbi->tile_list_outbuf, hstart2, vstart2); | 
 |           break; | 
 |         case 2: | 
 |           aom_yv12_partial_copy_v(cur_frame, hstart1, hend1, vstart1, vend1, | 
 |                                   &pbi->tile_list_outbuf, hstart2, vstart2); | 
 |           break; | 
 |         default: assert(0); | 
 |       } | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | // Only called while large_scale_tile = 1. | 
 | // | 
 | // On success, returns the tile list OBU size. On failure, sets | 
 | // pbi->common.error.error_code and returns 0. | 
 | static uint32_t read_and_decode_one_tile_list(AV1Decoder *pbi, | 
 |                                               struct aom_read_bit_buffer *rb, | 
 |                                               const uint8_t *data, | 
 |                                               const uint8_t *data_end, | 
 |                                               const uint8_t **p_data_end, | 
 |                                               int *frame_decoding_finished) { | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   uint32_t tile_list_payload_size = 0; | 
 |   const int num_tiles = cm->tiles.cols * cm->tiles.rows; | 
 |   const int start_tile = 0; | 
 |   const int end_tile = num_tiles - 1; | 
 |   int i = 0; | 
 |  | 
 |   // Process the tile list info. | 
 |   pbi->output_frame_width_in_tiles_minus_1 = aom_rb_read_literal(rb, 8); | 
 |   pbi->output_frame_height_in_tiles_minus_1 = aom_rb_read_literal(rb, 8); | 
 |   pbi->tile_count_minus_1 = aom_rb_read_literal(rb, 16); | 
 |   if (pbi->tile_count_minus_1 > MAX_TILES - 1) { | 
 |     pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |     return 0; | 
 |   } | 
 |  | 
 |   // Allocate output frame buffer for the tile list. | 
 |   alloc_tile_list_buffer(pbi); | 
 |  | 
 |   uint32_t tile_list_info_bytes = 4; | 
 |   tile_list_payload_size += tile_list_info_bytes; | 
 |   data += tile_list_info_bytes; | 
 |  | 
 |   int tile_idx = 0; | 
 |   for (i = 0; i <= pbi->tile_count_minus_1; i++) { | 
 |     // Process 1 tile. | 
 |     // Reset the bit reader. | 
 |     rb->bit_offset = 0; | 
 |     rb->bit_buffer = data; | 
 |  | 
 |     // Read out the tile info. | 
 |     uint32_t tile_info_bytes = 5; | 
 |     // Set reference for each tile. | 
 |     int ref_idx = aom_rb_read_literal(rb, 8); | 
 |     if (ref_idx >= MAX_EXTERNAL_REFERENCES) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |     av1_set_reference_dec(cm, cm->remapped_ref_idx[0], 1, | 
 |                           &pbi->ext_refs.refs[ref_idx]); | 
 |  | 
 |     pbi->dec_tile_row = aom_rb_read_literal(rb, 8); | 
 |     pbi->dec_tile_col = aom_rb_read_literal(rb, 8); | 
 |     if (pbi->dec_tile_row < 0 || pbi->dec_tile_col < 0 || | 
 |         pbi->dec_tile_row >= cm->tiles.rows || | 
 |         pbi->dec_tile_col >= cm->tiles.cols) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |  | 
 |     pbi->coded_tile_data_size = aom_rb_read_literal(rb, 16) + 1; | 
 |     data += tile_info_bytes; | 
 |     if ((size_t)(data_end - data) < pbi->coded_tile_data_size) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |  | 
 |     av1_decode_tg_tiles_and_wrapup(pbi, data, data + pbi->coded_tile_data_size, | 
 |                                    p_data_end, start_tile, end_tile, 0); | 
 |     uint32_t tile_payload_size = (uint32_t)(*p_data_end - data); | 
 |  | 
 |     tile_list_payload_size += tile_info_bytes + tile_payload_size; | 
 |  | 
 |     // Update data ptr for next tile decoding. | 
 |     data = *p_data_end; | 
 |     assert(data <= data_end); | 
 |  | 
 |     // Copy the decoded tile to the tile list output buffer. | 
 |     copy_decoded_tile_to_tile_list_buffer(pbi, tile_idx); | 
 |     tile_idx++; | 
 |   } | 
 |  | 
 |   *frame_decoding_finished = 1; | 
 |   return tile_list_payload_size; | 
 | } | 
 |  | 
 | // Returns the last nonzero byte index in 'data'. If there is no nonzero byte in | 
 | // 'data', returns -1. | 
 | static int get_last_nonzero_byte_index(const uint8_t *data, size_t sz) { | 
 |   // Scan backward and return on the first nonzero byte. | 
 |   int i = (int)sz - 1; | 
 |   while (i >= 0 && data[i] == 0) { | 
 |     --i; | 
 |   } | 
 |   return i; | 
 | } | 
 |  | 
 | // Allocates metadata that was read and adds it to the decoders metadata array. | 
 | static void alloc_read_metadata(AV1Decoder *const pbi, | 
 |                                 OBU_METADATA_TYPE metadata_type, | 
 |                                 const uint8_t *data, size_t sz, | 
 |                                 aom_metadata_insert_flags_t insert_flag) { | 
 |   if (!pbi->metadata) { | 
 |     pbi->metadata = aom_img_metadata_array_alloc(0); | 
 |     if (!pbi->metadata) { | 
 |       aom_internal_error(&pbi->error, AOM_CODEC_MEM_ERROR, | 
 |                          "Failed to allocate metadata array"); | 
 |     } | 
 |   } | 
 |   aom_metadata_t *metadata = | 
 |       aom_img_metadata_alloc(metadata_type, data, sz, insert_flag); | 
 |   if (!metadata) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_MEM_ERROR, | 
 |                        "Error allocating metadata"); | 
 |   } | 
 |   aom_metadata_t **metadata_array = | 
 |       (aom_metadata_t **)realloc(pbi->metadata->metadata_array, | 
 |                                  (pbi->metadata->sz + 1) * sizeof(metadata)); | 
 |   if (!metadata_array) { | 
 |     aom_img_metadata_free(metadata); | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_MEM_ERROR, | 
 |                        "Error growing metadata array"); | 
 |   } | 
 |   pbi->metadata->metadata_array = metadata_array; | 
 |   pbi->metadata->metadata_array[pbi->metadata->sz] = metadata; | 
 |   pbi->metadata->sz++; | 
 | } | 
 |  | 
 | // On failure, calls aom_internal_error() and does not return. | 
 | static void read_metadata_itut_t35(AV1Decoder *const pbi, const uint8_t *data, | 
 |                                    size_t sz) { | 
 |   if (sz == 0) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "itu_t_t35_country_code is missing"); | 
 |   } | 
 |   int country_code_size = 1; | 
 |   if (*data == 0xFF) { | 
 |     if (sz == 1) { | 
 |       aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                          "itu_t_t35_country_code_extension_byte is missing"); | 
 |     } | 
 |     ++country_code_size; | 
 |   } | 
 |   int end_index = get_last_nonzero_byte_index(data, sz); | 
 |   if (end_index < country_code_size) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "No trailing bits found in ITU-T T.35 metadata OBU"); | 
 |   } | 
 |   // itu_t_t35_payload_bytes is byte aligned. Section 6.7.2 of the spec says: | 
 |   //   itu_t_t35_payload_bytes shall be bytes containing data registered as | 
 |   //   specified in Recommendation ITU-T T.35. | 
 |   // Therefore the first trailing byte should be 0x80. | 
 |   if (data[end_index] != 0x80) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "The last nonzero byte of the ITU-T T.35 metadata OBU " | 
 |                        "is 0x%02x, should be 0x80.", | 
 |                        data[end_index]); | 
 |   } | 
 |   alloc_read_metadata(pbi, OBU_METADATA_TYPE_ITUT_T35, data, end_index, | 
 |                       AOM_MIF_ANY_FRAME); | 
 | } | 
 |  | 
 | // On success, returns the number of bytes read from 'data'. On failure, calls | 
 | // aom_internal_error() and does not return. | 
 | static size_t read_metadata_hdr_cll(AV1Decoder *const pbi, const uint8_t *data, | 
 |                                     size_t sz) { | 
 |   const size_t kHdrCllPayloadSize = 4; | 
 |   if (sz < kHdrCllPayloadSize) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "Incorrect HDR CLL metadata payload size"); | 
 |   } | 
 |   alloc_read_metadata(pbi, OBU_METADATA_TYPE_HDR_CLL, data, kHdrCllPayloadSize, | 
 |                       AOM_MIF_ANY_FRAME); | 
 |   return kHdrCllPayloadSize; | 
 | } | 
 |  | 
 | // On success, returns the number of bytes read from 'data'. On failure, calls | 
 | // aom_internal_error() and does not return. | 
 | static size_t read_metadata_hdr_mdcv(AV1Decoder *const pbi, const uint8_t *data, | 
 |                                      size_t sz) { | 
 |   const size_t kMdcvPayloadSize = 24; | 
 |   if (sz < kMdcvPayloadSize) { | 
 |     aom_internal_error(&pbi->error, AOM_CODEC_CORRUPT_FRAME, | 
 |                        "Incorrect HDR MDCV metadata payload size"); | 
 |   } | 
 |   alloc_read_metadata(pbi, OBU_METADATA_TYPE_HDR_MDCV, data, kMdcvPayloadSize, | 
 |                       AOM_MIF_ANY_FRAME); | 
 |   return kMdcvPayloadSize; | 
 | } | 
 |  | 
 | static void scalability_structure(struct aom_read_bit_buffer *rb) { | 
 |   const int spatial_layers_cnt_minus_1 = aom_rb_read_literal(rb, 2); | 
 |   const int spatial_layer_dimensions_present_flag = aom_rb_read_bit(rb); | 
 |   const int spatial_layer_description_present_flag = aom_rb_read_bit(rb); | 
 |   const int temporal_group_description_present_flag = aom_rb_read_bit(rb); | 
 |   // scalability_structure_reserved_3bits must be set to zero and be ignored by | 
 |   // decoders. | 
 |   aom_rb_read_literal(rb, 3); | 
 |  | 
 |   if (spatial_layer_dimensions_present_flag) { | 
 |     for (int i = 0; i <= spatial_layers_cnt_minus_1; i++) { | 
 |       aom_rb_read_literal(rb, 16); | 
 |       aom_rb_read_literal(rb, 16); | 
 |     } | 
 |   } | 
 |   if (spatial_layer_description_present_flag) { | 
 |     for (int i = 0; i <= spatial_layers_cnt_minus_1; i++) { | 
 |       aom_rb_read_literal(rb, 8); | 
 |     } | 
 |   } | 
 |   if (temporal_group_description_present_flag) { | 
 |     const int temporal_group_size = aom_rb_read_literal(rb, 8); | 
 |     for (int i = 0; i < temporal_group_size; i++) { | 
 |       aom_rb_read_literal(rb, 3); | 
 |       aom_rb_read_bit(rb); | 
 |       aom_rb_read_bit(rb); | 
 |       const int temporal_group_ref_cnt = aom_rb_read_literal(rb, 3); | 
 |       for (int j = 0; j < temporal_group_ref_cnt; j++) { | 
 |         aom_rb_read_literal(rb, 8); | 
 |       } | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | static void read_metadata_scalability(struct aom_read_bit_buffer *rb) { | 
 |   const int scalability_mode_idc = aom_rb_read_literal(rb, 8); | 
 |   if (scalability_mode_idc == SCALABILITY_SS) { | 
 |     scalability_structure(rb); | 
 |   } | 
 | } | 
 |  | 
 | static void read_metadata_timecode(struct aom_read_bit_buffer *rb) { | 
 |   aom_rb_read_literal(rb, 5);  // counting_type f(5) | 
 |   const int full_timestamp_flag = | 
 |       aom_rb_read_bit(rb);     // full_timestamp_flag f(1) | 
 |   aom_rb_read_bit(rb);         // discontinuity_flag (f1) | 
 |   aom_rb_read_bit(rb);         // cnt_dropped_flag f(1) | 
 |   aom_rb_read_literal(rb, 9);  // n_frames f(9) | 
 |   if (full_timestamp_flag) { | 
 |     aom_rb_read_literal(rb, 6);  // seconds_value f(6) | 
 |     aom_rb_read_literal(rb, 6);  // minutes_value f(6) | 
 |     aom_rb_read_literal(rb, 5);  // hours_value f(5) | 
 |   } else { | 
 |     const int seconds_flag = aom_rb_read_bit(rb);  // seconds_flag f(1) | 
 |     if (seconds_flag) { | 
 |       aom_rb_read_literal(rb, 6);                    // seconds_value f(6) | 
 |       const int minutes_flag = aom_rb_read_bit(rb);  // minutes_flag f(1) | 
 |       if (minutes_flag) { | 
 |         aom_rb_read_literal(rb, 6);                  // minutes_value f(6) | 
 |         const int hours_flag = aom_rb_read_bit(rb);  // hours_flag f(1) | 
 |         if (hours_flag) { | 
 |           aom_rb_read_literal(rb, 5);  // hours_value f(5) | 
 |         } | 
 |       } | 
 |     } | 
 |   } | 
 |   // time_offset_length f(5) | 
 |   const int time_offset_length = aom_rb_read_literal(rb, 5); | 
 |   if (time_offset_length) { | 
 |     // time_offset_value f(time_offset_length) | 
 |     aom_rb_read_literal(rb, time_offset_length); | 
 |   } | 
 | } | 
 |  | 
 | // Returns the last nonzero byte in 'data'. If there is no nonzero byte in | 
 | // 'data', returns 0. | 
 | // | 
 | // Call this function to check the following requirement in the spec: | 
 | //   This implies that when any payload data is present for this OBU type, at | 
 | //   least one byte of the payload data (including the trailing bit) shall not | 
 | //   be equal to 0. | 
 | static uint8_t get_last_nonzero_byte(const uint8_t *data, size_t sz) { | 
 |   // Scan backward and return on the first nonzero byte. | 
 |   size_t i = sz; | 
 |   while (i != 0) { | 
 |     --i; | 
 |     if (data[i] != 0) return data[i]; | 
 |   } | 
 |   return 0; | 
 | } | 
 |  | 
 | // Checks the metadata for correct syntax but ignores the parsed metadata. | 
 | // | 
 | // On success, returns the number of bytes read from 'data'. On failure, sets | 
 | // pbi->common.error.error_code and returns 0, or calls aom_internal_error() | 
 | // and does not return. | 
 | static size_t read_metadata(AV1Decoder *pbi, const uint8_t *data, size_t sz) { | 
 |   size_t type_length; | 
 |   uint64_t type_value; | 
 |   if (aom_uleb_decode(data, sz, &type_value, &type_length) < 0) { | 
 |     pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |     return 0; | 
 |   } | 
 |   const OBU_METADATA_TYPE metadata_type = (OBU_METADATA_TYPE)type_value; | 
 |   if (metadata_type == 0 || metadata_type >= 6) { | 
 |     // If metadata_type is reserved for future use or a user private value, | 
 |     // ignore the entire OBU and just check trailing bits. | 
 |     if (get_last_nonzero_byte(data + type_length, sz - type_length) == 0) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |     return sz; | 
 |   } | 
 |   if (metadata_type == OBU_METADATA_TYPE_ITUT_T35) { | 
 |     // read_metadata_itut_t35() checks trailing bits. | 
 |     read_metadata_itut_t35(pbi, data + type_length, sz - type_length); | 
 |     return sz; | 
 |   } else if (metadata_type == OBU_METADATA_TYPE_HDR_CLL) { | 
 |     size_t bytes_read = | 
 |         type_length + | 
 |         read_metadata_hdr_cll(pbi, data + type_length, sz - type_length); | 
 |     if (get_last_nonzero_byte(data + bytes_read, sz - bytes_read) != 0x80) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |     return sz; | 
 |   } else if (metadata_type == OBU_METADATA_TYPE_HDR_MDCV) { | 
 |     size_t bytes_read = | 
 |         type_length + | 
 |         read_metadata_hdr_mdcv(pbi, data + type_length, sz - type_length); | 
 |     if (get_last_nonzero_byte(data + bytes_read, sz - bytes_read) != 0x80) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |     return sz; | 
 |   } | 
 |  | 
 |   struct aom_read_bit_buffer rb; | 
 |   av1_init_read_bit_buffer(pbi, &rb, data + type_length, data + sz); | 
 |   if (metadata_type == OBU_METADATA_TYPE_SCALABILITY) { | 
 |     read_metadata_scalability(&rb); | 
 |   } else { | 
 |     assert(metadata_type == OBU_METADATA_TYPE_TIMECODE); | 
 |     read_metadata_timecode(&rb); | 
 |   } | 
 |   if (av1_check_trailing_bits(pbi, &rb) != 0) { | 
 |     // pbi->error.error_code is already set. | 
 |     return 0; | 
 |   } | 
 |   assert((rb.bit_offset & 7) == 0); | 
 |   return type_length + (rb.bit_offset >> 3); | 
 | } | 
 |  | 
 | // On success, returns 'sz'. On failure, sets pbi->common.error.error_code and | 
 | // returns 0. | 
 | static size_t read_padding(AV1_COMMON *const cm, const uint8_t *data, | 
 |                            size_t sz) { | 
 |   // The spec allows a padding OBU to be header-only (i.e., obu_size = 0). So | 
 |   // check trailing bits only if sz > 0. | 
 |   if (sz > 0) { | 
 |     // The payload of a padding OBU is byte aligned. Therefore the first | 
 |     // trailing byte should be 0x80. See https://crbug.com/aomedia/2393. | 
 |     const uint8_t last_nonzero_byte = get_last_nonzero_byte(data, sz); | 
 |     if (last_nonzero_byte != 0x80) { | 
 |       cm->error->error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return 0; | 
 |     } | 
 |   } | 
 |   return sz; | 
 | } | 
 |  | 
 | // On success, returns a boolean that indicates whether the decoding of the | 
 | // current frame is finished. On failure, sets pbi->error.error_code and | 
 | // returns -1. | 
 | int aom_decode_frame_from_obus(struct AV1Decoder *pbi, const uint8_t *data, | 
 |                                const uint8_t *data_end, | 
 |                                const uint8_t **p_data_end) { | 
 |   AV1_COMMON *const cm = &pbi->common; | 
 |   int frame_decoding_finished = 0; | 
 |   int is_first_tg_obu_received = 1; | 
 |   // Whenever pbi->seen_frame_header is set to 1, frame_header is set to the | 
 |   // beginning of the frame_header_obu and frame_header_size is set to its | 
 |   // size. This allows us to check if a redundant frame_header_obu is a copy | 
 |   // of the previous frame_header_obu. | 
 |   // | 
 |   // Initialize frame_header to a dummy nonnull pointer, otherwise the Clang | 
 |   // Static Analyzer in clang 7.0.1 will falsely warn that a null pointer is | 
 |   // passed as an argument to a 'nonnull' parameter of memcmp(). The initial | 
 |   // value will not be used. | 
 |   const uint8_t *frame_header = data; | 
 |   uint32_t frame_header_size = 0; | 
 |   ObuHeader obu_header; | 
 |   memset(&obu_header, 0, sizeof(obu_header)); | 
 |   pbi->seen_frame_header = 0; | 
 |   pbi->next_start_tile = 0; | 
 |   pbi->num_tile_groups = 0; | 
 |  | 
 |   if (data_end < data) { | 
 |     pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |     return -1; | 
 |   } | 
 |  | 
 |   // Reset pbi->camera_frame_header_ready to 0 if cm->tiles.large_scale = 0. | 
 |   if (!cm->tiles.large_scale) pbi->camera_frame_header_ready = 0; | 
 |  | 
 |   // decode frame as a series of OBUs | 
 |   while (!frame_decoding_finished && pbi->error.error_code == AOM_CODEC_OK) { | 
 |     struct aom_read_bit_buffer rb; | 
 |     size_t payload_size = 0; | 
 |     size_t decoded_payload_size = 0; | 
 |     size_t obu_payload_offset = 0; | 
 |     size_t bytes_read = 0; | 
 |     const size_t bytes_available = data_end - data; | 
 |  | 
 |     if (bytes_available == 0 && !pbi->seen_frame_header) { | 
 |       *p_data_end = data; | 
 |       pbi->error.error_code = AOM_CODEC_OK; | 
 |       break; | 
 |     } | 
 |  | 
 |     aom_codec_err_t status = | 
 |         aom_read_obu_header_and_size(data, bytes_available, pbi->is_annexb, | 
 |                                      &obu_header, &payload_size, &bytes_read); | 
 |  | 
 |     if (status != AOM_CODEC_OK) { | 
 |       pbi->error.error_code = status; | 
 |       return -1; | 
 |     } | 
 |  | 
 |     // Record obu size header information. | 
 |     pbi->obu_size_hdr.data = data + obu_header.size; | 
 |     pbi->obu_size_hdr.size = bytes_read - obu_header.size; | 
 |  | 
 |     // Note: aom_read_obu_header_and_size() takes care of checking that this | 
 |     // doesn't cause 'data' to advance past 'data_end'. | 
 |     data += bytes_read; | 
 |  | 
 |     if ((size_t)(data_end - data) < payload_size) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return -1; | 
 |     } | 
 |  | 
 |     cm->temporal_layer_id = obu_header.temporal_layer_id; | 
 |     cm->spatial_layer_id = obu_header.spatial_layer_id; | 
 |  | 
 |     if (obu_header.type != OBU_TEMPORAL_DELIMITER && | 
 |         obu_header.type != OBU_SEQUENCE_HEADER) { | 
 |       // don't decode obu if it's not in current operating mode | 
 |       if (!is_obu_in_current_operating_point(pbi, &obu_header)) { | 
 |         data += payload_size; | 
 |         continue; | 
 |       } | 
 |     } | 
 |  | 
 |     av1_init_read_bit_buffer(pbi, &rb, data, data + payload_size); | 
 |  | 
 |     switch (obu_header.type) { | 
 |       case OBU_TEMPORAL_DELIMITER: | 
 |         decoded_payload_size = read_temporal_delimiter_obu(); | 
 |         if (pbi->seen_frame_header) { | 
 |           // A new temporal unit has started, but the frame in the previous | 
 |           // temporal unit is incomplete. | 
 |           pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |           return -1; | 
 |         } | 
 |         break; | 
 |       case OBU_SEQUENCE_HEADER: | 
 |         decoded_payload_size = read_sequence_header_obu(pbi, &rb); | 
 |         if (pbi->error.error_code != AOM_CODEC_OK) return -1; | 
 |         // The sequence header should not change in the middle of a frame. | 
 |         if (pbi->sequence_header_changed && pbi->seen_frame_header) { | 
 |           pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |           return -1; | 
 |         } | 
 |         break; | 
 |       case OBU_FRAME_HEADER: | 
 |       case OBU_REDUNDANT_FRAME_HEADER: | 
 |       case OBU_FRAME: | 
 |         if (obu_header.type == OBU_REDUNDANT_FRAME_HEADER) { | 
 |           if (!pbi->seen_frame_header) { | 
 |             pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |             return -1; | 
 |           } | 
 |         } else { | 
 |           // OBU_FRAME_HEADER or OBU_FRAME. | 
 |           if (pbi->seen_frame_header) { | 
 |             pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |             return -1; | 
 |           } | 
 |         } | 
 |         // Only decode first frame header received | 
 |         if (!pbi->seen_frame_header || | 
 |             (cm->tiles.large_scale && !pbi->camera_frame_header_ready)) { | 
 |           frame_header_size = read_frame_header_obu( | 
 |               pbi, &rb, data, p_data_end, obu_header.type != OBU_FRAME); | 
 |           frame_header = data; | 
 |           pbi->seen_frame_header = 1; | 
 |           if (!pbi->ext_tile_debug && cm->tiles.large_scale) | 
 |             pbi->camera_frame_header_ready = 1; | 
 |         } else { | 
 |           // Verify that the frame_header_obu is identical to the original | 
 |           // frame_header_obu. | 
 |           if (frame_header_size > payload_size || | 
 |               memcmp(data, frame_header, frame_header_size) != 0) { | 
 |             pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |             return -1; | 
 |           } | 
 |           assert(rb.bit_offset == 0); | 
 |           rb.bit_offset = 8 * frame_header_size; | 
 |         } | 
 |  | 
 |         decoded_payload_size = frame_header_size; | 
 |         pbi->frame_header_size = frame_header_size; | 
 |         cm->cur_frame->temporal_id = obu_header.temporal_layer_id; | 
 |         cm->cur_frame->spatial_id = obu_header.spatial_layer_id; | 
 |  | 
 |         if (cm->show_existing_frame) { | 
 |           if (obu_header.type == OBU_FRAME) { | 
 |             pbi->error.error_code = AOM_CODEC_UNSUP_BITSTREAM; | 
 |             return -1; | 
 |           } | 
 |           frame_decoding_finished = 1; | 
 |           pbi->seen_frame_header = 0; | 
 |           break; | 
 |         } | 
 |  | 
 |         // In large scale tile coding, decode the common camera frame header | 
 |         // before any tile list OBU. | 
 |         if (!pbi->ext_tile_debug && pbi->camera_frame_header_ready) { | 
 |           frame_decoding_finished = 1; | 
 |           // Skip the rest of the frame data. | 
 |           decoded_payload_size = payload_size; | 
 |           // Update data_end. | 
 |           *p_data_end = data_end; | 
 |           break; | 
 |         } | 
 |  | 
 |         if (obu_header.type != OBU_FRAME) break; | 
 |         obu_payload_offset = frame_header_size; | 
 |         // Byte align the reader before reading the tile group. | 
 |         // byte_alignment() has set pbi->error.error_code if it returns -1. | 
 |         if (byte_alignment(cm, &rb)) return -1; | 
 |         AOM_FALLTHROUGH_INTENDED;  // fall through to read tile group. | 
 |       case OBU_TILE_GROUP: | 
 |         if (!pbi->seen_frame_header) { | 
 |           pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |           return -1; | 
 |         } | 
 |         if (obu_payload_offset > payload_size) { | 
 |           pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |           return -1; | 
 |         } | 
 |         decoded_payload_size += read_one_tile_group_obu( | 
 |             pbi, &rb, is_first_tg_obu_received, data + obu_payload_offset, | 
 |             data + payload_size, p_data_end, &frame_decoding_finished, | 
 |             obu_header.type == OBU_FRAME); | 
 |         if (pbi->error.error_code != AOM_CODEC_OK) return -1; | 
 |         is_first_tg_obu_received = 0; | 
 |         if (frame_decoding_finished) { | 
 |           pbi->seen_frame_header = 0; | 
 |           pbi->next_start_tile = 0; | 
 |         } | 
 |         pbi->num_tile_groups++; | 
 |         break; | 
 |       case OBU_METADATA: | 
 |         decoded_payload_size = read_metadata(pbi, data, payload_size); | 
 |         if (pbi->error.error_code != AOM_CODEC_OK) return -1; | 
 |         break; | 
 |       case OBU_TILE_LIST: | 
 |         if (CONFIG_NORMAL_TILE_MODE) { | 
 |           pbi->error.error_code = AOM_CODEC_UNSUP_BITSTREAM; | 
 |           return -1; | 
 |         } | 
 |  | 
 |         // This OBU type is purely for the large scale tile coding mode. | 
 |         // The common camera frame header has to be already decoded. | 
 |         if (!pbi->camera_frame_header_ready) { | 
 |           pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |           return -1; | 
 |         } | 
 |  | 
 |         cm->tiles.large_scale = 1; | 
 |         av1_set_single_tile_decoding_mode(cm); | 
 |         decoded_payload_size = | 
 |             read_and_decode_one_tile_list(pbi, &rb, data, data + payload_size, | 
 |                                           p_data_end, &frame_decoding_finished); | 
 |         if (pbi->error.error_code != AOM_CODEC_OK) return -1; | 
 |         break; | 
 |       case OBU_PADDING: | 
 |         decoded_payload_size = read_padding(cm, data, payload_size); | 
 |         if (pbi->error.error_code != AOM_CODEC_OK) return -1; | 
 |         break; | 
 |       default: | 
 |         // Skip unrecognized OBUs | 
 |         if (payload_size > 0 && | 
 |             get_last_nonzero_byte(data, payload_size) == 0) { | 
 |           pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |           return -1; | 
 |         } | 
 |         decoded_payload_size = payload_size; | 
 |         break; | 
 |     } | 
 |  | 
 |     // Check that the signalled OBU size matches the actual amount of data read | 
 |     if (decoded_payload_size > payload_size) { | 
 |       pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |       return -1; | 
 |     } | 
 |  | 
 |     // If there are extra padding bytes, they should all be zero | 
 |     while (decoded_payload_size < payload_size) { | 
 |       uint8_t padding_byte = data[decoded_payload_size++]; | 
 |       if (padding_byte != 0) { | 
 |         pbi->error.error_code = AOM_CODEC_CORRUPT_FRAME; | 
 |         return -1; | 
 |       } | 
 |     } | 
 |  | 
 |     data += payload_size; | 
 |   } | 
 |  | 
 |   if (pbi->error.error_code != AOM_CODEC_OK) return -1; | 
 |   return frame_decoding_finished; | 
 | } |