| Message ID | 1492786781-77792-1-git-send-email-sharpbai@gmail.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Apr 21, 2017 at 10:59:41PM +0800, sharpbai@gmail.com wrote: > From: sharpbai <sharpbai@gmail.com> > > Bug example: > > ffmpeg -i a.mp3 -c:a mp3 -ab 32k -ar 44100 -ac 1 b.mp3 > > The duration of the generated file b.mp3 is wrong on ios safari browser from ios7 to ios10. > --- > libavformat/mp3enc.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) ios safari browser doesnt support the xing header ? [...]
ios safari browser support the xing header, and the duration of the mp3 file with xing header is correct. But with "Info" replaced "Xing" in xing header in CBR mode, ios safari browser does not skip the first frame and using the first frame header(the bitrate in header has changed to enlarge frame size as xing frame needs at least 177 bytes) to calculate duration. 2017-04-23 0:29 GMT+08:00 Michael Niedermayer <michael@niedermayer.cc>: > On Fri, Apr 21, 2017 at 10:59:41PM +0800, sharpbai@gmail.com wrote: >> From: sharpbai <sharpbai@gmail.com> >> >> Bug example: >> >> ffmpeg -i a.mp3 -c:a mp3 -ab 32k -ar 44100 -ac 1 b.mp3 >> >> The duration of the generated file b.mp3 is wrong on ios safari browser from ios7 to ios10. >> --- >> libavformat/mp3enc.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) > > ios safari browser doesnt support the xing header ? > > [...] > > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel >
On Fri, 21 Apr 2017 22:59:41 +0800 sharpbai@gmail.com wrote: > From: sharpbai <sharpbai@gmail.com> > > Bug example: > > ffmpeg -i a.mp3 -c:a mp3 -ab 32k -ar 44100 -ac 1 b.mp3 > > The duration of the generated file b.mp3 is wrong on ios safari browser from ios7 to ios10. > --- > libavformat/mp3enc.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/libavformat/mp3enc.c b/libavformat/mp3enc.c > index 3cbf7bd..a55dbf4 100644 > --- a/libavformat/mp3enc.c > +++ b/libavformat/mp3enc.c > @@ -395,8 +395,13 @@ static void mp3_update_xing(AVFormatContext *s) > int i, rg_size; > > /* replace "Xing" identification string with "Info" for CBR files. */ > - if (!mp3->has_variable_bitrate) > + if (!mp3->has_variable_bitrate) { > AV_WL32(mp3->xing_frame + mp3->xing_offset, MKTAG('I', 'n', 'f', 'o')); > + av_log(s, AV_LOG_WARNING, > + "This is a CBR mp3 file. But its first frame header might be wrong, " > + "which result in file duration incorrect on ios browser. " > + "Please add \"-write_xing false\" to avoid this problem.\n"); > + } > > AV_WB32(mp3->xing_frame + mp3->xing_offset + 8, mp3->frames); > AV_WB32(mp3->xing_frame + mp3->xing_offset + 12, mp3->size); What's "ios browser". I'm not sure what this message is supposed to help either - I think until now we usually haven't added warnings when using or not using options that result in problems with specific consuming applications. The commit message subject line should not be longer than 72 characters.
diff --git a/libavformat/mp3enc.c b/libavformat/mp3enc.c index 3cbf7bd..a55dbf4 100644 --- a/libavformat/mp3enc.c +++ b/libavformat/mp3enc.c @@ -395,8 +395,13 @@ static void mp3_update_xing(AVFormatContext *s) int i, rg_size; /* replace "Xing" identification string with "Info" for CBR files. */ - if (!mp3->has_variable_bitrate) + if (!mp3->has_variable_bitrate) { AV_WL32(mp3->xing_frame + mp3->xing_offset, MKTAG('I', 'n', 'f', 'o')); + av_log(s, AV_LOG_WARNING, + "This is a CBR mp3 file. But its first frame header might be wrong, " + "which result in file duration incorrect on ios browser. " + "Please add \"-write_xing false\" to avoid this problem.\n"); + } AV_WB32(mp3->xing_frame + mp3->xing_offset + 8, mp3->frames); AV_WB32(mp3->xing_frame + mp3->xing_offset + 12, mp3->size);
From: sharpbai <sharpbai@gmail.com> Bug example: ffmpeg -i a.mp3 -c:a mp3 -ab 32k -ar 44100 -ac 1 b.mp3 The duration of the generated file b.mp3 is wrong on ios safari browser from ios7 to ios10. --- libavformat/mp3enc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)