Clean-up write_film_grain_params()
Various refactoring and clean-up to write_film_grain_params():
* Instead of the confusing logic with flip_back_update_parameters_flag,
simply copy current_frame->film_grain_params to
cur_frame->film_grain_params in finalize_encoded_frame before setting
the update_parameters flag appropriately.
* Iterate the film grain parameters random seed in
finalize_encoded_frame instead of write_film_grain_params
* Previously a few assignments silently fixed erroneous/meaningless
state/configuration: replace these with assertions to make it clearer
what's happening.
After these changes write_film_grain_params() can take a const AV1_COMP
and only has the effect of writing to the bitstream. This is part of my
work at removing side effects and other unexpected actions from
av1_pack_bitstream and below, which is itself part of wider
restructuring and refactoring with the goal of achieving a clean API
separation at the entry to the low-level encoder.
BUG=aomedia:2244
Change-Id: I0162b0d48c3207212d6ce7ce6d7a6d8015294241
diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index 6fe8fdb..5786317 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -2465,25 +2465,19 @@
cm->buffer_model.frame_presentation_time_length);
}
-static void write_film_grain_params(AV1_COMP *cpi,
+static void write_film_grain_params(const AV1_COMP *const cpi,
struct aom_write_bit_buffer *wb) {
- AV1_COMMON *const cm = &cpi->common;
- aom_film_grain_t *pars = &cm->film_grain_params;
-
- cm->cur_frame->film_grain_params = *pars;
+ const AV1_COMMON *const cm = &cpi->common;
+ const aom_film_grain_t *const pars = &cm->cur_frame->film_grain_params;
aom_wb_write_bit(wb, pars->apply_grain);
if (!pars->apply_grain) return;
aom_wb_write_literal(wb, pars->random_seed, 16);
- pars->random_seed += 3381; // Changing random seed for film grain
- if (!pars->random_seed) // Random seed should not be zero
- pars->random_seed += 7391;
if (cm->current_frame.frame_type == INTER_FRAME)
aom_wb_write_bit(wb, pars->update_parameters);
- else
- pars->update_parameters = 1;
+
if (!pars->update_parameters) {
int ref_frame, ref_idx;
for (ref_frame = LAST_FRAME; ref_frame < REF_FRAMES; ref_frame++) {
@@ -2507,16 +2501,16 @@
aom_wb_write_literal(wb, pars->scaling_points_y[i][1], 8);
}
- if (!cm->seq_params.monochrome)
+ if (!cm->seq_params.monochrome) {
aom_wb_write_bit(wb, pars->chroma_scaling_from_luma);
- else
- pars->chroma_scaling_from_luma = 0; // for monochrome override to 0
+ } else {
+ assert(!pars->chroma_scaling_from_luma);
+ }
if (cm->seq_params.monochrome || pars->chroma_scaling_from_luma ||
((cm->seq_params.subsampling_x == 1) &&
(cm->seq_params.subsampling_y == 1) && (pars->num_y_points == 0))) {
- pars->num_cb_points = 0;
- pars->num_cr_points = 0;
+ assert(pars->num_cb_points == 0 && pars->num_cr_points == 0);
} else {
aom_wb_write_literal(wb, pars->num_cb_points, 4); // max 10
for (int i = 0; i < pars->num_cb_points; i++) {
@@ -3124,19 +3118,9 @@
if (!frame_is_intra_only(cm)) write_global_motion(cpi, wb);
if (seq_params->film_grain_params_present &&
- (cm->show_frame || cm->showable_frame)) {
- int flip_back_update_parameters_flag = 0;
- if (current_frame->frame_type != INTER_FRAME &&
- cm->film_grain_params.update_parameters == 0) {
- cm->film_grain_params.update_parameters = 1;
- flip_back_update_parameters_flag = 1;
- }
+ (cm->show_frame || cm->showable_frame))
write_film_grain_params(cpi, wb);
- if (flip_back_update_parameters_flag)
- cm->film_grain_params.update_parameters = 0;
- }
-
if (cm->large_scale_tile) write_ext_tile_info(cm, saved_wb, wb);
}
