| /* |
| * Copyright (c) 2016, 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. |
| */ |
| |
| // Simple Decoder |
| // ============== |
| // |
| // This is an example of a simple decoder loop. It takes an input file |
| // containing the compressed data (in IVF format), passes it through the |
| // decoder, and writes the decompressed frames to disk. Other decoder |
| // examples build upon this one. |
| // |
| // The details of the IVF format have been elided from this example for |
| // simplicity of presentation, as IVF files will not generally be used by |
| // your application. In general, an IVF file consists of a file header, |
| // followed by a variable number of frames. Each frame consists of a frame |
| // header followed by a variable length payload. The length of the payload |
| // is specified in the first four bytes of the frame header. The payload is |
| // the raw compressed data. |
| // |
| // Standard Includes |
| // ----------------- |
| // For decoders, you only have to include `aom_decoder.h` and then any |
| // header files for the specific codecs you use. In this case, we're using |
| // aom. |
| // |
| // Initializing The Codec |
| // ---------------------- |
| // The libaom decoder is initialized by the call to aom_codec_dec_init(). |
| // Determining the codec interface to use is handled by AvxVideoReader and the |
| // functions prefixed with aom_video_reader_. Discussion of those functions is |
| // beyond the scope of this example, but the main gist is to open the input file |
| // and parse just enough of it to determine if it's a AVx file and which AVx |
| // codec is contained within the file. |
| // Note the NULL pointer passed to aom_codec_dec_init(). We do that in this |
| // example because we want the algorithm to determine the stream configuration |
| // (width/height) and allocate memory automatically. |
| // |
| // Decoding A Frame |
| // ---------------- |
| // Once the frame has been read into memory, it is decoded using the |
| // `aom_codec_decode` function. The call takes a pointer to the data |
| // (`frame`) and the length of the data (`frame_size`). No application data |
| // is associated with the frame in this example, so the `user_priv` |
| // parameter is NULL. |
| // |
| // Codecs may produce a variable number of output frames for every call to |
| // `aom_codec_decode`. These frames are retrieved by the |
| // `aom_codec_get_frame` iterator function. The iterator variable `iter` is |
| // initialized to NULL each time `aom_codec_decode` is called. |
| // `aom_codec_get_frame` is called in a loop, returning a pointer to a |
| // decoded image or NULL to indicate the end of list. |
| // |
| // Processing The Decoded Data |
| // --------------------------- |
| // In this example, we simply write the encoded data to disk. It is |
| // important to honor the image's `stride` values. |
| // |
| // Cleanup |
| // ------- |
| // The `aom_codec_destroy` call frees any memory allocated by the codec. |
| // |
| // Error Handling |
| // -------------- |
| // This example does not special case any error return codes. If there was |
| // an error, a descriptive message is printed and the program exits. With |
| // few exceptions, aom_codec functions return an enumerated error status, |
| // with the value `0` indicating success. |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "aom/aom_decoder.h" |
| #include "common/tools_common.h" |
| #include "common/video_reader.h" |
| |
| static const char *exec_name; |
| |
| void usage_exit(void) { |
| fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name); |
| exit(EXIT_FAILURE); |
| } |
| |
| int main(int argc, char **argv) { |
| int frame_cnt = 0; |
| FILE *outfile = NULL; |
| AvxVideoReader *reader = NULL; |
| const AvxVideoInfo *info = NULL; |
| |
| exec_name = argv[0]; |
| |
| if (argc != 3) die("Invalid number of arguments."); |
| |
| reader = aom_video_reader_open(argv[1]); |
| if (!reader) die("Failed to open %s for reading.", argv[1]); |
| |
| if (!(outfile = fopen(argv[2], "wb"))) |
| die("Failed to open %s for writing.", argv[2]); |
| |
| info = aom_video_reader_get_info(reader); |
| |
| aom_codec_iface_t *decoder = get_aom_decoder_by_fourcc(info->codec_fourcc); |
| if (!decoder) die("Unknown input codec."); |
| |
| printf("Using %s\n", aom_codec_iface_name(decoder)); |
| |
| aom_codec_ctx_t codec; |
| if (aom_codec_dec_init(&codec, decoder, NULL, 0)) |
| die("Failed to initialize decoder."); |
| |
| while (aom_video_reader_read_frame(reader)) { |
| aom_codec_iter_t iter = NULL; |
| aom_image_t *img = NULL; |
| size_t frame_size = 0; |
| const unsigned char *frame = |
| aom_video_reader_get_frame(reader, &frame_size); |
| if (aom_codec_decode(&codec, frame, frame_size, NULL)) |
| die_codec(&codec, "Failed to decode frame."); |
| |
| while ((img = aom_codec_get_frame(&codec, &iter)) != NULL) { |
| aom_img_write(img, outfile); |
| ++frame_cnt; |
| } |
| } |
| |
| printf("Processed %d frames.\n", frame_cnt); |
| if (aom_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec"); |
| |
| printf("Play: ffplay -f rawvideo -pix_fmt yuv420p -s %dx%d %s\n", |
| info->frame_width, info->frame_height, argv[2]); |
| |
| aom_video_reader_close(reader); |
| |
| fclose(outfile); |
| |
| return EXIT_SUCCESS; |
| } |