[FFmpeg-devel] [PATCH 1/5] lavf: add FFERROR_REDO to let demuxer return no packet.

[Nicolas George]

Signed-off-by: Nicolas George <george at nsup.org>
---
 libavformat/internal.h | 6 ++++++
 libavformat/utils.c    | 5 +++++
 2 files changed, 11 insertions(+)


Apparently, the most unhappyness was caused by the error code in the public
API. This is not the case here.


diff --git a/libavformat/internal.h b/libavformat/internal.h
index ee86094..0f684bd 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -516,4 +516,10 @@ int ff_copy_whitelists(AVFormatContext *dst, AVFormatContext *src);
 int ffio_open2_wrapper(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
                        const AVIOInterruptCB *int_cb, AVDictionary **options);
 
+/**
+ * Returned by demuxers to indicate that data was consumed but discarded
+ * (ignored streams or junk data). The framework will re-call the demuxer.
+ */
+#define FFERROR_REDO FFERRTAG( 'R','E','D','O')
+
 #endif /* AVFORMAT_INTERNAL_H */
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 8cb7d38..83e2f73 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -680,6 +680,11 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
         av_init_packet(pkt);
         ret = s->iformat->read_packet(s, pkt);
         if (ret < 0) {
+            /* Some demuxer (FLV, MPEG-PS) return FFERROR_REDO when they
+               data and discard it (ignored streams, junk, extradata).
+               We must re-call the demuxer to get the real packet. */
+            if (ret == FFERROR_REDO)
+                continue;
             if (!pktl || ret == AVERROR(EAGAIN))
                 return ret;
             for (i = 0; i < s->nb_streams; i++) {
-- 
2.6.2