[FFmpeg-devel] [PATCH] nvdec/vc1: add marker insertion logic
averne
averne381 at gmail.com
Wed Mar 12 19:41:53 EET 2025
Bump
Le 04/03/2025 à 18:17, averne a écrit :
>
>
> ---
> Insert the relevant marker into the bitstream on
> slice submission.
> This is analogous to the logic found in DXVA and
> D3D hwaccels.
>
> Fixes decoding of various VC-1 streams, eg.:
> https://drive.google.com/file/d/1WJyiRhcdU4FHTW3sVMitS7UdrZM1NBy-/view?usp=sharing
>
> This was investigated using my nvdec tracing tool:
> https://github.com/averne/NvdecTrace
>
> Signed-off-by: averne <averne381 at gmail.com>
> ---
> libavcodec/nvdec_vc1.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/libavcodec/nvdec_vc1.c b/libavcodec/nvdec_vc1.c
> index fbfba1ecb43421573ef8fea1e37a2425c272edc9..2726574a26583b0cfc28bdec5595c15bdc465ff8 100644
> --- a/libavcodec/nvdec_vc1.c
> +++ b/libavcodec/nvdec_vc1.c
> @@ -22,6 +22,7 @@
>
> #include "config_components.h"
>
> +#include "libavutil/mem.h"
> #include "avcodec.h"
> #include "hwaccel_internal.h"
> #include "internal.h"
> @@ -107,6 +108,51 @@ static int nvdec_vc1_start_frame(AVCodecContext *avctx, const uint8_t *buffer, u
> return 0;
> }
>
> +static int nvdec_vc1_decode_slice(AVCodecContext *avctx, const uint8_t *buffer,
> + uint32_t size)
> +{
> + NVDECContext *ctx = avctx->internal->hwaccel_priv_data;
> + const VC1Context *v = avctx->priv_data;
> + uint32_t marker;
> + int marker_size;
> + void *tmp;
> +
> + if (avctx->codec_id != AV_CODEC_ID_VC1) {
> + marker_size = 0;
> + } else {
> + if (ctx->bitstream_len)
> + marker = VC1_CODE_SLICE;
> + else if (v->profile == PROFILE_ADVANCED && v->fcm == ILACE_FIELD && v->second_field)
> + marker = VC1_CODE_FIELD;
> + else
> + marker = VC1_CODE_FRAME;
> +
> + marker_size = (size >= sizeof(marker) && AV_RB32(buffer) != marker) ? sizeof(marker) : 0;
> + }
> +
> + tmp = av_fast_realloc(ctx->bitstream_internal, &ctx->bitstream_allocated,
> + ctx->bitstream_len + size + marker_size);
> + if (!tmp)
> + return AVERROR(ENOMEM);
> + ctx->bitstream = ctx->bitstream_internal = tmp;
> +
> + tmp = av_fast_realloc(ctx->slice_offsets, &ctx->slice_offsets_allocated,
> + (ctx->nb_slices + 1) * sizeof(*ctx->slice_offsets));
> + if (!tmp)
> + return AVERROR(ENOMEM);
> + ctx->slice_offsets = tmp;
> +
> + if (marker_size)
> + AV_WB32(ctx->bitstream_internal + ctx->bitstream_len, marker);
> +
> + memcpy(ctx->bitstream_internal + ctx->bitstream_len + marker_size, buffer, size);
> + ctx->slice_offsets[ctx->nb_slices] = ctx->bitstream_len;
> + ctx->bitstream_len += size + marker_size;
> + ctx->nb_slices++;
> +
> + return 0;
> +}
> +
> static int nvdec_vc1_frame_params(AVCodecContext *avctx,
> AVBufferRef *hw_frames_ctx)
> {
> @@ -121,7 +167,7 @@ const FFHWAccel ff_vc1_nvdec_hwaccel = {
> .p.pix_fmt = AV_PIX_FMT_CUDA,
> .start_frame = nvdec_vc1_start_frame,
> .end_frame = ff_nvdec_simple_end_frame,
> - .decode_slice = ff_nvdec_simple_decode_slice,
> + .decode_slice = nvdec_vc1_decode_slice,
> .frame_params = nvdec_vc1_frame_params,
> .init = ff_nvdec_decode_init,
> .uninit = ff_nvdec_decode_uninit,
> @@ -136,7 +182,7 @@ const FFHWAccel ff_wmv3_nvdec_hwaccel = {
> .p.pix_fmt = AV_PIX_FMT_CUDA,
> .start_frame = nvdec_vc1_start_frame,
> .end_frame = ff_nvdec_simple_end_frame,
> - .decode_slice = ff_nvdec_simple_decode_slice,
> + .decode_slice = nvdec_vc1_decode_slice,
> .frame_params = nvdec_vc1_frame_params,
> .init = ff_nvdec_decode_init,
> .uninit = ff_nvdec_decode_uninit,
>
> ---
> base-commit: f76195ff656d6bea68feee783160652e2b3e3d60
> change-id: 20250304-nvdec-vc1-marker2-53d6bd30ee99
>
> Best regards,
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