From 261cd929e06b716b3bcc944c96fdf94371b3a7ed Mon Sep 17 00:00:00 2001 From: James Almer Date: Sun, 4 Dec 2022 15:35:58 -0300 Subject: [PATCH] avcodec/mpeg4videodec: duplicate the last decoded frame when the last coded frame was skipped This ensures the video stream duration is not lost after decoding. Signed-off-by: James Almer --- libavcodec/h263dec.c | 13 +++++++++++++ libavcodec/mpegvideo.h | 1 + 2 files changed, 14 insertions(+) diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c index ac7a8521e5..0a2d7487a8 100644 --- a/libavcodec/h263dec.c +++ b/libavcodec/h263dec.c @@ -430,6 +430,18 @@ int ff_h263_decode_frame(AVCodecContext *avctx, AVFrame *pict, return ret; s->next_picture_ptr = NULL; + *got_frame = 1; + } else if (s->skipped_last_frame && s->current_picture_ptr) { + /* Output the last picture we decoded again if the stream ended with + * an NVOP */ + if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0) + return ret; + /* Copy props from the last input packet. Otherwise, props from the last + * returned picture would be reused */ + if ((ret = ff_decode_frame_props(avctx, pict)) < 0) + return ret; + s->current_picture_ptr = NULL; + *got_frame = 1; } @@ -500,6 +512,7 @@ retry: s->extradata_parsed = 1; } ret = ff_mpeg4_decode_picture_header(avctx->priv_data, &s->gb, 0, 0); + s->skipped_last_frame = (ret == FRAME_SKIPPED); } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) { ret = ff_intel_h263_decode_picture_header(s); } else if (CONFIG_FLV_DECODER && s->h263_flv) { diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h index 6440b906b1..42275953b9 100644 --- a/libavcodec/mpegvideo.h +++ b/libavcodec/mpegvideo.h @@ -175,6 +175,7 @@ typedef struct MpegEncContext { Picture *last_picture_ptr; ///< pointer to the previous picture. Picture *next_picture_ptr; ///< pointer to the next picture (for bidir pred) Picture *current_picture_ptr; ///< pointer to the current picture + int skipped_last_frame; int last_dc[3]; ///< last DC values for MPEG-1 int16_t *dc_val_base; int16_t *dc_val[3]; ///< used for MPEG-4 DC prediction, all 3 arrays must be continuous