[FFmpeg-trac] #7321(ffprobe:reopened): Sample format for mp2 audio channel is incorrectly determined as fltp rather than s16p
FFmpeg
trac at avcodec.org
Fri Oct 19 14:27:36 EEST 2018
#7321: Sample format for mp2 audio channel is incorrectly determined as fltp
rather than s16p
------------------------------------+------------------------------------
Reporter: haertel | Owner:
Type: defect | Status: reopened
Priority: normal | Component: ffprobe
Version: git-master | Resolution:
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
------------------------------------+------------------------------------
Changes (by klassikmann):
* status: closed => reopened
* resolution: invalid =>
* component: undetermined => ffprobe
Comment:
Background:
The codec mp2 is heavily used in DVB, both cable and SAT. In particular
DVB-Audio is based on mp2.
Problem description:
My DVB SAT receiver streams digital audio to my music server (Pi,
ArchLinux, RuneAudio, mpd with ffmpeg plugin). After the upgrade of mpd to
0.20.21 and ffmpeg to 4.0.2 the sample format is detected as fltp instead
of s16p. Consequence: The ffmpeg plugin invoked by mpd performs a
(meaningless) conversion from 48000:f:2 to 48000:32:2 producing noise.
The error can be detected in ffprobe, i.e. it has nothing to do with the
ffmpeg API.
ffprobe -show_format -show_streams hr1.mp2
Previous (correct) situation:
ffprobe 3.4.4:
> Input #0, mp3, from 'hr1.mp2':
> Duration: 00:00:16.85, start: 0.000000, bitrate: 384 kb/s
> Stream #0:0: Audio: mp2, 48000 Hz, stereo, '''s16p''', 384 kb/s
> [STREAM]
> index=0
> codec_name=mp2
> codec_long_name=MP2 (MPEG audio layer 2)
> profile=unknown
> codec_type=audio
> codec_time_base=1/48000
> codec_tag_string=[0][0][0][0]
> codec_tag=0x0000
> sample_fmt='''s16p'''
> sample_rate=48000
> channels=2
> channel_layout=stereo
Actual (erroneous) situation:
ffprobe 4.0.2:
> Input #0, mp3, from 'hr1.mp2':
> Duration: 00:00:16.85, start: 0.000000, bitrate: 384 kb/s
> Stream #0:0: Audio: mp2, 48000 Hz, stereo, '''fltp''', 384 kb/s
> [STREAM]
> index=0
> codec_name=mp2
> codec_long_name=MP2 (MPEG audio layer 2)
> profile=unknown
> codec_type=audio
> codec_time_base=1/48000
> codec_tag_string=[0][0][0][0]
> codec_tag=0x0000
> sample_fmt='''fltp'''
> sample_rate=48000
> channels=2
> channel_layout=stereo
--
Ticket URL: <https://trac.ffmpeg.org/ticket/7321#comment:2>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list