[FFmpeg-cvslog] avcodec/hevc: Add alpha layer support
Zhao Zhili
git at videolan.org
Mon Feb 17 10:27:30 EET 2025
ffmpeg | branch: master | Zhao Zhili <zhilizhao at tencent.com> | Tue Feb 11 21:21:25 2025 +0800| [f926b6045522c5f9887a108f5d9b6ae017e9ba02] | committer: Zhao Zhili
avcodec/hevc: Add alpha layer support
Signed-off-by: Zhao Zhili <zhilizhao at tencent.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f926b6045522c5f9887a108f5d9b6ae017e9ba02
---
libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++-
libavcodec/hevc/hevcdec.h | 2 ++
libavcodec/hevc/refs.c | 34 +++++++++++++++++++++-
3 files changed, 107 insertions(+), 2 deletions(-)
diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
index e9c045f7a1..f71edf213b 100644
--- a/libavcodec/hevc/hevcdec.c
+++ b/libavcodec/hevc/hevcdec.c
@@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
return 0;
}
+int ff_hevc_is_alpha_video(const HEVCContext *s)
+{
+ const HEVCVPS *vps = s->vps;
+ int ret = 0;
+
+ if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
+ return 0;
+
+ /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
+ * than alpha cannot reach here.
+ */
+ ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
+
+ av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
+ ret ? "is" : "not");
+
+ return ret;
+}
+
static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
{
unsigned layers_active_output = 0, highest_layer;
@@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
s->layers_active_output = 1;
s->layers_active_decode = 1;
+ if (ff_hevc_is_alpha_video(s)) {
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
+
+ if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
+ return 0;
+
+ s->layers_active_decode = (1 << vps->nb_layers) - 1;
+ s->layers_active_output = 1;
+
+ return 0;
+ }
+
// nothing requested - decode base layer only
if (!s->nb_view_ids)
return 0;
@@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
return 0;
}
+static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
+ enum AVPixelFormat pix_fmt)
+{
+ switch (pix_fmt) {
+ case AV_PIX_FMT_YUV420P:
+ case AV_PIX_FMT_YUVJ420P:
+ return AV_PIX_FMT_YUVA420P;
+ case AV_PIX_FMT_YUV420P10:
+ return AV_PIX_FMT_YUVA420P10;
+ case AV_PIX_FMT_YUV444P:
+ return AV_PIX_FMT_YUVA444P;
+ case AV_PIX_FMT_YUV422P:
+ return AV_PIX_FMT_YUVA422P;
+ case AV_PIX_FMT_YUV422P10LE:
+ return AV_PIX_FMT_YUVA422P10LE;
+ case AV_PIX_FMT_YUV444P10:
+ return AV_PIX_FMT_YUVA444P10;
+ case AV_PIX_FMT_YUV444P12:
+ return AV_PIX_FMT_YUVA444P12;
+ case AV_PIX_FMT_YUV422P12:
+ return AV_PIX_FMT_YUVA422P12;
+ default:
+ av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
+ av_get_pix_fmt_name(pix_fmt));
+ return AV_PIX_FMT_NONE;
+ }
+}
+
static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
{
#define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
@@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
CONFIG_HEVC_VDPAU_HWACCEL + \
CONFIG_HEVC_VULKAN_HWACCEL)
- enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
+ enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
+ enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
int ret;
+ if (ff_hevc_is_alpha_video(s))
+ alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
+
switch (sps->pix_fmt) {
case AV_PIX_FMT_YUV420P:
case AV_PIX_FMT_YUVJ420P:
@@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
break;
}
+ if (alpha_fmt != AV_PIX_FMT_NONE)
+ *fmt++ = alpha_fmt;
*fmt++ = sps->pix_fmt;
*fmt = AV_PIX_FMT_NONE;
@@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
!sps->vui.common.video_signal_type_present_flag)
pix_fmt = sps_base->pix_fmt;
+ // Ignore range mismatch between base layer and alpha layer
+ if (ff_hevc_is_alpha_video(s) &&
+ sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
+ pix_fmt == AV_PIX_FMT_YUVJ420P)
+ pix_fmt = sps_base->pix_fmt;
+
if (pix_fmt != sps_base->pix_fmt ||
sps->width != sps_base->width ||
sps->height != sps_base->height) {
diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
index 4e95035688..b2b725b5cd 100644
--- a/libavcodec/hevc/hevcdec.h
+++ b/libavcodec/hevc/hevcdec.h
@@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
+int ff_hevc_is_alpha_video(const HEVCContext *s);
+
extern const uint8_t ff_hevc_qpel_extra_before[4];
extern const uint8_t ff_hevc_qpel_extra_after[4];
extern const uint8_t ff_hevc_qpel_extra[4];
diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
index dd7f7f95a8..1277cb2e7f 100644
--- a/libavcodec/hevc/refs.c
+++ b/libavcodec/hevc/refs.c
@@ -79,6 +79,31 @@ void ff_hevc_flush_dpb(HEVCContext *s)
}
}
+static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
+{
+ AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
+ uintptr_t data = (uintptr_t)alpha->data[0];
+ int ret;
+
+ for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
+ AVBufferRef *buf = alpha->buf[i];
+ uintptr_t buf_begin = (uintptr_t)buf->data;
+
+ if (data >= buf_begin && data < buf_begin + buf->size) {
+ ret = av_buffer_replace(&alpha->buf[i], base_a);
+ if (ret < 0)
+ return ret;
+
+ alpha->linesize[0] = base->linesize[3];
+ alpha->data[0] = base->data[3];
+
+ return 0;
+ }
+ }
+
+ return AVERROR_BUG;
+}
+
static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
{
const HEVCVPS *vps = l->sps->vps;
@@ -103,7 +128,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
}
// add view ID side data if it's nontrivial
- if (vps->nb_layers > 1 || view_id) {
+ if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
&frame->f->nb_side_data,
@@ -162,6 +187,13 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
goto fail;
frame->pps = av_refstruct_ref_c(s->pps);
+ if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
+ AVFrame *alpha = frame->f;
+ AVFrame *base = s->layers[0].cur_frame->f;
+ ret = replace_alpha_plane(alpha, base);
+ if (ret < 0)
+ goto fail;
+ }
return frame;
fail:
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