[FFmpeg-devel] [PATCH] avcodec/hevcdec: apply H.274 film grain
Niklas Haas
ffmpeg at haasn.xyz
Fri Sep 24 12:55:54 EEST 2021
From: Niklas Haas <git at haasn.dev>
Similar in spirit and design to 66845cffc3bbb, but slightly simpler due
to the lack of interlaced frames in HEVC. See that commit for more
details.
For the seed value, since no specification for this appears to exist, I
semi-arbitrarily decided to base it off the POC id alone, since there's
no analog of the idr_pic_id in HEVC's I-frames. This design is stable
across remuxes and seeks, but changes for adjacent frames with a period
that's typically long enough not to be noticeable, which makes it
satisfy all of the requirements that a film grain seed should have.
Tested with and without threading, using a patch to insert film grain
metadata artificially (for lack of real files containing film grain).
---
libavcodec/hevc_refs.c | 4 ++-
libavcodec/hevcdec.c | 57 ++++++++++++++++++++++++++++++++++++++++--
libavcodec/hevcdec.h | 5 ++++
3 files changed, 63 insertions(+), 3 deletions(-)
diff --git a/libavcodec/hevc_refs.c b/libavcodec/hevc_refs.c
index 4f6d985ae6..0a532451d0 100644
--- a/libavcodec/hevc_refs.c
+++ b/libavcodec/hevc_refs.c
@@ -38,6 +38,8 @@ void ff_hevc_unref_frame(HEVCContext *s, HEVCFrame *frame, int flags)
frame->flags &= ~flags;
if (!frame->flags) {
ff_thread_release_buffer(s->avctx, &frame->tf);
+ ff_thread_release_buffer(s->avctx, &frame->tf_grain);
+ frame->needs_fg = 0;
av_buffer_unref(&frame->tab_mvf_buf);
frame->tab_mvf = NULL;
@@ -208,7 +210,7 @@ int ff_hevc_output_frame(HEVCContext *s, AVFrame *out, int flush)
if (nb_output) {
HEVCFrame *frame = &s->DPB[min_idx];
- ret = av_frame_ref(out, frame->frame);
+ ret = av_frame_ref(out, frame->needs_fg ? frame->frame_grain : frame->frame);
if (frame->flags & HEVC_FRAME_FLAG_BUMPING)
ff_hevc_unref_frame(s, frame, HEVC_FRAME_FLAG_OUTPUT | HEVC_FRAME_FLAG_BUMPING);
else
diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index 57a61752a3..a86320a034 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -2881,14 +2881,14 @@ static int set_side_data(HEVCContext *s)
s->sei.timecode.num_clock_ts = 0;
}
- if (s->sei.film_grain_characteristics.present &&
- (s->avctx->export_side_data & AV_CODEC_EXPORT_DATA_FILM_GRAIN)) {
+ if (s->sei.film_grain_characteristics.present) {
HEVCSEIFilmGrainCharacteristics *fgc = &s->sei.film_grain_characteristics;
AVFilmGrainParams *fgp = av_film_grain_params_create_side_data(out);
if (!fgp)
return AVERROR(ENOMEM);
fgp->type = AV_FILM_GRAIN_PARAMS_H274;
+ fgp->seed = s->ref->poc; /* no poc_offset in HEVC */
fgp->codec.h274.model_id = fgc->model_id;
if (fgc->separate_colour_description_present_flag) {
@@ -2983,6 +2983,17 @@ static int hevc_frame_start(HEVCContext *s)
s->ref->frame->key_frame = IS_IRAP(s);
+ s->ref->needs_fg = s->sei.film_grain_characteristics.present &&
+ !(s->avctx->export_side_data & AV_CODEC_EXPORT_DATA_FILM_GRAIN);
+
+ if (s->ref->needs_fg) {
+ s->ref->frame_grain->format = s->ref->frame->format;
+ s->ref->frame_grain->width = s->ref->frame->width;
+ s->ref->frame_grain->height = s->ref->frame->height;
+ if ((ret = ff_thread_get_buffer(s->avctx, &s->ref->tf_grain, 0)) < 0)
+ goto fail;
+ }
+
ret = set_side_data(s);
if (ret < 0)
goto fail;
@@ -3009,6 +3020,32 @@ fail:
return ret;
}
+static int hevc_frame_end(HEVCContext *s)
+{
+ HEVCFrame *out = s->ref;
+ const AVFrameSideData *sd;
+ int ret;
+
+ if (out->needs_fg) {
+ sd = av_frame_get_side_data(out->frame, AV_FRAME_DATA_FILM_GRAIN_PARAMS);
+ av_assert0(out->frame_grain->buf[0] && sd);
+ ret = ff_h274_apply_film_grain(out->frame_grain, out->frame, &s->h274db,
+ (AVFilmGrainParams *) sd->data);
+ av_frame_remove_side_data(out->frame, AV_FRAME_DATA_FILM_GRAIN_PARAMS);
+
+ if (ret < 0) {
+ av_log(s->avctx, AV_LOG_WARNING, "Failed synthesizing film "
+ "grain, ignoring: %s\n", av_err2str(ret));
+ out->needs_fg = 0;
+ } else {
+ if ((ret = av_frame_copy_props(out->frame_grain, out->frame)) < 0)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
static int decode_nal_unit(HEVCContext *s, const H2645NAL *nal)
{
HEVCLocalContext *lc = s->HEVClc;
@@ -3167,6 +3204,9 @@ static int decode_nal_unit(HEVCContext *s, const H2645NAL *nal)
else
ctb_addr_ts = hls_slice_data(s);
if (ctb_addr_ts >= (s->ps.sps->ctb_width * s->ps.sps->ctb_height)) {
+ ret = hevc_frame_end(s);
+ if (ret < 0)
+ goto fail;
s->is_decoded = 1;
}
@@ -3426,6 +3466,13 @@ static int hevc_ref_frame(HEVCContext *s, HEVCFrame *dst, HEVCFrame *src)
if (ret < 0)
return ret;
+ if (src->needs_fg) {
+ ret = ff_thread_ref_frame(&dst->tf_grain, &src->tf_grain);
+ if (ret < 0)
+ return ret;
+ dst->needs_fg = 1;
+ }
+
dst->tab_mvf_buf = av_buffer_ref(src->tab_mvf_buf);
if (!dst->tab_mvf_buf)
goto fail;
@@ -3478,6 +3525,7 @@ static av_cold int hevc_decode_free(AVCodecContext *avctx)
for (i = 0; i < FF_ARRAY_ELEMS(s->DPB); i++) {
ff_hevc_unref_frame(s, &s->DPB[i], ~0);
av_frame_free(&s->DPB[i].frame);
+ av_frame_free(&s->DPB[i].frame_grain);
}
ff_hevc_ps_uninit(&s->ps);
@@ -3531,6 +3579,11 @@ static av_cold int hevc_init_context(AVCodecContext *avctx)
if (!s->DPB[i].frame)
goto fail;
s->DPB[i].tf.f = s->DPB[i].frame;
+
+ s->DPB[i].frame_grain = av_frame_alloc();
+ if (!s->DPB[i].frame_grain)
+ goto fail;
+ s->DPB[i].tf_grain.f = s->DPB[i].frame_grain;
}
s->max_ra = INT_MAX;
diff --git a/libavcodec/hevcdec.h b/libavcodec/hevcdec.h
index 482638a8e5..8963aa83ae 100644
--- a/libavcodec/hevcdec.h
+++ b/libavcodec/hevcdec.h
@@ -39,6 +39,7 @@
#include "hevc_ps.h"
#include "hevc_sei.h"
#include "hevcdsp.h"
+#include "h274.h"
#include "internal.h"
#include "thread.h"
#include "videodsp.h"
@@ -395,7 +396,10 @@ typedef struct DBParams {
typedef struct HEVCFrame {
AVFrame *frame;
+ AVFrame *frame_grain;
ThreadFrame tf;
+ ThreadFrame tf_grain;
+ int needs_fg; /* 1 if grain needs to be applied by the decoder */
MvField *tab_mvf;
RefPicList *refPicList;
RefPicListTab **rpl_tab;
@@ -525,6 +529,7 @@ typedef struct HEVCContext {
HEVCDSPContext hevcdsp;
VideoDSPContext vdsp;
BswapDSPContext bdsp;
+ H274FilmGrainDatabase h274db;
int8_t *qp_y_tab;
uint8_t *horizontal_bs;
uint8_t *vertical_bs;
--
2.33.0
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