From 584ac1ad0bb5e8c8c51f82b952ebeeca62e58b96 Mon Sep 17 00:00:00 2001 From: Maxime Jourdan Date: Fri, 30 Aug 2019 11:34:52 -0700 Subject: [PATCH] avcodec/v4l2_m2m_dec: fix dropped packets while decoding * FFmpeg retrieves a packet from the bitstream * It attempts to get an input buffer (from its own list or by dequeuing one from the driver) * If no input buffer is found, the bitstream packet is dropped instead of scheduled for trying again later It's an issue that showed especially at high speeds (like using `-f null -` as output parameters). Signed-off-by: Aman Gupta --- libavcodec/v4l2_m2m.h | 1 + libavcodec/v4l2_m2m_dec.c | 21 ++++++++++++++++----- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/libavcodec/v4l2_m2m.h b/libavcodec/v4l2_m2m.h index c860e96ef52..456281f48c5 100644 --- a/libavcodec/v4l2_m2m.h +++ b/libavcodec/v4l2_m2m.h @@ -56,6 +56,7 @@ typedef struct V4L2m2mContext { /* null frame/packet received */ int draining; + AVPacket buf_pkt; /* Reference to self; only valid while codec is active. */ AVBufferRef *self_ref; diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c index 686e1303875..d0f1c41f9de 100644 --- a/libavcodec/v4l2_m2m_dec.c +++ b/libavcodec/v4l2_m2m_dec.c @@ -133,9 +133,14 @@ static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame) AVPacket avpkt = {0}; int ret; - ret = ff_decode_get_packet(avctx, &avpkt); - if (ret < 0 && ret != AVERROR_EOF) - return ret; + if (s->buf_pkt.size) { + avpkt = s->buf_pkt; + memset(&s->buf_pkt, 0, sizeof(AVPacket)); + } else { + ret = ff_decode_get_packet(avctx, &avpkt); + if (ret < 0 && ret != AVERROR_EOF) + return ret; + } if (s->draining) goto dequeue; @@ -144,6 +149,8 @@ static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame) if (ret < 0) { if (ret != AVERROR(EAGAIN)) return ret; + + s->buf_pkt = avpkt; /* no input buffers available, continue dequeing */ } @@ -161,7 +168,8 @@ static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame) } dequeue: - av_packet_unref(&avpkt); + if (!s->buf_pkt.size) + av_packet_unref(&avpkt); return ff_v4l2_context_dequeue_frame(capture, frame, -1); } @@ -207,7 +215,10 @@ static av_cold int v4l2_decode_init(AVCodecContext *avctx) static av_cold int v4l2_decode_close(AVCodecContext *avctx) { - return ff_v4l2_m2m_codec_end(avctx->priv_data); + V4L2m2mPriv *priv = avctx->priv_data; + V4L2m2mContext* s = priv->context; + av_packet_unref(&s->buf_pkt); + return ff_v4l2_m2m_codec_end(priv); } #define OFFSET(x) offsetof(V4L2m2mPriv, x) -- 2.39.2