lavd/v4l2: correctly handle error conditions in mmap_read_frame()

In particular:

1) save errno before it (possibly) gets overwritten by other calls
2) do not forget to enqueue the buffer again in case of error

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Giorgio Vazzana 2013-03-09 14:36:56 +01:00 committed by Michael Niedermayer
parent 982070c113
commit 0286b42540

View File

@ -610,15 +610,17 @@ static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
res = av_new_packet(pkt, buf.bytesused);
if (res < 0) {
av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
return res;
}
memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
res = v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf);
if (res < 0) {
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
res = AVERROR(errno);
av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
av_free_packet(pkt);
return AVERROR(errno);
return res;
}
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
} else {
@ -636,7 +638,8 @@ static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
* allocate a buffer for memcpying into it
*/
av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
res = v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf);
if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
return AVERROR(ENOMEM);
}
@ -647,6 +650,9 @@ static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
buf_descriptor, 0);
if (!pkt->buf) {
av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
av_freep(&buf_descriptor);
return AVERROR(ENOMEM);
}