| Message ID | 20200817092508.97973-1-p.vanderspek@bluebillywig.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [FFmpeg-devel] avformat/flvdec: RtmpSampleAccess no longer breaks stream detection | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/make | success | Make finished |
| andriy/make_fate | success | Make fate finished |
On Mon, Aug 17, 2020 at 11:25:08AM +0200, Peter van der Spek wrote: > Since release 4.2, FFmpeg fails to detect the correct streams in an RTMP > stream that contains a |RtmpSampleAccess AMF object prior to the > onMetaData AMF object. In the debug log it would show "[flv] Unknown > type |RtmpSampleAccess". > > With this change the RTMP streams are correctly detected when there > is a |RtmpSampleAccess object prior to the onMetaData object. > > Signed-off-by: Peter van der Spek <p.vanderspek@bluebillywig.com> > --- > libavformat/flvdec.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Do you have a testcase? Is this documented somewhere? thx [...]
It took me some time to figure out where this |RtmpSampleAccess packet came from. It turns out that this is an undocumented AMF packet that is used to transfer the state of the documented Client.audioSampleAccess and Client.videoSampleAccess state to the client. This post gave me some clues: https://nicolas.brousse.info/blog/flash-how-to-fix-the-security-sandbox-violation-bitmapdata-draw/ These sampleAccess states are used to allow a (Flash) client to access the raw video and audio data. The states are pushed by the server as a IRtmpSampleAccess packet. Adobe FMS, Wowza, Red5, etc… all support this mechanism. I’m able to reproduce this issue with RTMP streams pulled from a Nginx-RTMP server (https://github.com/arut/nginx-rtmp-module). Client.audioSampleAccess and Client.videoSampleAccess are documented here: https://helpx.adobe.com/adobe-media-server/ssaslr/client-class.html#client_audiosampleaccess https://helpx.adobe.com/adobe-media-server/ssaslr/client-class.html#client_videosampleaccess Best, Peter On 18 Aug 2020, 14:46 +0200, Michael Niedermayer <michael@niedermayer.cc>, wrote: > > Do you have a testcase? > Is this documented somewhere? > > thx > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > In a rich man's house there is no place to spit but his face. > -- Diogenes of Sinope > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Peter van der Spek: > Since release 4.2, FFmpeg fails to detect the correct streams in an RTMP > stream that contains a |RtmpSampleAccess AMF object prior to the > onMetaData AMF object. In the debug log it would show "[flv] Unknown > type |RtmpSampleAccess". > > With this change the RTMP streams are correctly detected when there > is a |RtmpSampleAccess object prior to the onMetaData object. > > Signed-off-by: Peter van der Spek <p.vanderspek@bluebillywig.com> > --- > libavformat/flvdec.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c > index 0862273..d480d0b 100644 > --- a/libavformat/flvdec.c > +++ b/libavformat/flvdec.c > @@ -715,7 +715,7 @@ static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) > if (!strcmp(buffer, "onCaptionInfo")) > return TYPE_ONCAPTIONINFO; > > - if (strcmp(buffer, "onMetaData") && strcmp(buffer, "onCuePoint")) { > + if (strcmp(buffer, "onMetaData") && strcmp(buffer, "onCuePoint") && strcmp(buffer, "|RtmpSampleAccess")) { > av_log(s, AV_LOG_DEBUG, "Unknown type %s\n", buffer); > return TYPE_UNKNOWN; > } > Which commit broke it? (That should be included in the commit message.) - Andreas
diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c index 0862273..d480d0b 100644 --- a/libavformat/flvdec.c +++ b/libavformat/flvdec.c @@ -715,7 +715,7 @@ static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) if (!strcmp(buffer, "onCaptionInfo")) return TYPE_ONCAPTIONINFO; - if (strcmp(buffer, "onMetaData") && strcmp(buffer, "onCuePoint")) { + if (strcmp(buffer, "onMetaData") && strcmp(buffer, "onCuePoint") && strcmp(buffer, "|RtmpSampleAccess")) { av_log(s, AV_LOG_DEBUG, "Unknown type %s\n", buffer); return TYPE_UNKNOWN; }
Since release 4.2, FFmpeg fails to detect the correct streams in an RTMP stream that contains a |RtmpSampleAccess AMF object prior to the onMetaData AMF object. In the debug log it would show "[flv] Unknown type |RtmpSampleAccess". With this change the RTMP streams are correctly detected when there is a |RtmpSampleAccess object prior to the onMetaData object. Signed-off-by: Peter van der Spek <p.vanderspek@bluebillywig.com> --- libavformat/flvdec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)