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decode: be more explicit about storing the last packet properties

The current code stores a pointer to the packet passed to the decoder,
which is then used during get_buffer() for timestamps and side data
passthrough. However, since this is a pointer to user data which we do
not own, storing it is potentially dangerous. It is also ill defined for
the new decoding API with split input/output.

Fix this problem by making an explicit internally owned copy of the
packet properties.
tags/n3.4
Anton Khirnov 8 years ago
parent
commit
549d0bdca5
4 changed files with 32 additions and 17 deletions
  1. +20
    -13
      libavcodec/decode.c
  2. +3
    -3
      libavcodec/internal.h
  3. +1
    -1
      libavcodec/pthread_frame.c
  4. +8
    -0
      libavcodec/utils.c

+ 20
- 13
libavcodec/decode.c View File

@@ -99,6 +99,14 @@ fail2:
return 0;
}

static int extract_packet_props(AVCodecInternal *avci, const AVPacket *pkt)
{
av_packet_unref(avci->last_pkt_props);
if (pkt)
return av_packet_copy_props(avci->last_pkt_props, pkt);
return 0;
}

static int unrefcount_frame(AVCodecInternal *avci, AVFrame *frame)
{
int ret;
@@ -304,7 +312,10 @@ int attribute_align_arg avcodec_decode_video2(AVCodecContext *avctx, AVFrame *pi
return AVERROR(ENOSYS);
}

avctx->internal->pkt = avpkt;
ret = extract_packet_props(avci, avpkt);
if (ret < 0)
return ret;

ret = apply_param_change(avctx, avpkt);
if (ret < 0)
return ret;
@@ -368,7 +379,9 @@ int attribute_align_arg avcodec_decode_audio4(AVCodecContext *avctx,
return AVERROR(ENOSYS);
}

avctx->internal->pkt = avpkt;
ret = extract_packet_props(avci, avpkt);
if (ret < 0)
return ret;

if (!avpkt->data && avpkt->size) {
av_log(avctx, AV_LOG_ERROR, "invalid packet: NULL data, size != 0\n");
@@ -408,7 +421,10 @@ int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
{
int ret;

avctx->internal->pkt = avpkt;
ret = extract_packet_props(avctx->internal, avpkt);
if (ret < 0)
return ret;

*got_sub_ptr = 0;
ret = avctx->codec->decode(avctx, sub, got_sub_ptr, avpkt);
if (*got_sub_ptr)
@@ -739,7 +755,7 @@ int avcodec_default_get_buffer2(AVCodecContext *avctx, AVFrame *frame, int flags

int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame)
{
AVPacket *pkt = avctx->internal->pkt;
AVPacket *pkt = avctx->internal->last_pkt_props;
int i;
struct {
enum AVPacketSideDataType packet;
@@ -759,15 +775,6 @@ int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame)
frame->chroma_location = avctx->chroma_sample_location;

frame->reordered_opaque = avctx->reordered_opaque;
if (!pkt) {
#if FF_API_PKT_PTS
FF_DISABLE_DEPRECATION_WARNINGS
frame->pkt_pts = AV_NOPTS_VALUE;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
frame->pts = AV_NOPTS_VALUE;
return 0;
}

#if FF_API_PKT_PTS
FF_DISABLE_DEPRECATION_WARNINGS


+ 3
- 3
libavcodec/internal.h View File

@@ -131,10 +131,10 @@ typedef struct AVCodecInternal {
void *thread_ctx;

/**
* Current packet as passed into the decoder, to avoid having to pass the
* packet into every function.
* Properties (timestamps+side data) extracted from the last packet passed
* for decoding.
*/
AVPacket *pkt;
AVPacket *last_pkt_props;

/**
* hwaccel-specific private data


+ 1
- 1
libavcodec/pthread_frame.c View File

@@ -656,7 +656,7 @@ int ff_frame_thread_init(AVCodecContext *avctx)
}
*copy->internal = *src->internal;
copy->internal->thread_ctx = p;
copy->internal->pkt = &p->avpkt;
copy->internal->last_pkt_props = &p->avpkt;

if (!i) {
src = copy;


+ 8
- 0
libavcodec/utils.c View File

@@ -433,6 +433,12 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
goto free_and_end;
}

avctx->internal->last_pkt_props = av_packet_alloc();
if (!avctx->internal->last_pkt_props) {
ret = AVERROR(ENOMEM);
goto free_and_end;
}

if (codec->priv_data_size > 0) {
if (!avctx->priv_data) {
avctx->priv_data = av_mallocz(codec->priv_data_size);
@@ -713,6 +719,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
av_frame_free(&avctx->internal->to_free);
av_frame_free(&avctx->internal->buffer_frame);
av_packet_free(&avctx->internal->buffer_pkt);
av_packet_free(&avctx->internal->last_pkt_props);
av_freep(&avctx->internal->pool);
}
av_freep(&avctx->internal);
@@ -753,6 +760,7 @@ av_cold int avcodec_close(AVCodecContext *avctx)
av_frame_free(&avctx->internal->to_free);
av_frame_free(&avctx->internal->buffer_frame);
av_packet_free(&avctx->internal->buffer_pkt);
av_packet_free(&avctx->internal->last_pkt_props);
for (i = 0; i < FF_ARRAY_ELEMS(pool->pools); i++)
av_buffer_pool_uninit(&pool->pools[i]);
av_freep(&avctx->internal->pool);


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