@@ -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);

         }