CouldntDecodeError: Decoding failed. ffmpeg returned error code: 1

I’m having trouble getting pydub to work. The error message is listed below. I’ve reported the issue in detail on StackOverflow: here. I think this is an issue with ffmpeg, but honestly, I cant tell whether avlib or ffmpeg are running here. Is there a way to determine which library is being used?

In[5]: pydub.AudioSegment.from_file(".../sensorlog_2017-02-03_12-50-25-345_Dev26c5_Loc27_TypeAUDIO.m4a", "aac")
Traceback (most recent call last):
  File "...anaconda2/lib/python2.7/site-packages/IPython/core/interactiveshell.py", line 2881, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-5-607e3f2a62c3>", line 1, in <module>
    pydub.AudioSegment.from_file(".../sensorlog_2017-02-03_12-50-25-345_Dev26c5_Loc27_ActvEatingAT-DrinkingAT_TypeAUDIO.m4a", "aac")
  File ".../anaconda2/lib/python2.7/site-packages/pydub/audio_segment.py", line 472, in from_file
    raise CouldntDecodeError("Decoding failed. ffmpeg returned error code: {0}\n\nOutput from ffmpeg/avlib:\n\n{1}".format(p.returncode, p_err))
CouldntDecodeError: Decoding failed. ffmpeg returned error code: 1
Output from ffmpeg/avlib:
ffmpeg version 3.2.2 Copyright (c) 2000-2016 the FFmpeg developers
  built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  libavutil      55. 34.100 / 55. 34.100
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.100 / 57. 56.100
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libavresample   3.  1.  0 /  3.  1.  0
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
[aac @ 0x7f8485002e00] channel element 3.14 is not allocated
[aac @ 0x7f8485002e00] Sample rate index in program config element does not match the sample rate index configured by the container.
[aac @ 0x7f8485002e00] decode_pce: Input buffer exhausted before END element found
[aac @ 0x7f8485002e00] More than one AAC RDB per ADTS frame is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.
[aac @ 0x7f8485002e00] channel element 2.9 is not allocated
[aac @ 0x7f8485002200] decoding for stream 0 failed
[aac @ 0x7f8485002200] Estimating duration from bitrate, this may be inaccurate
[aac @ 0x7f8485002200] Could not find codec parameters for stream 0 (Audio: aac (LC), 4.0, fltp, 213 kb/s): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, aac, from '/var/folders/cm/1r6x6rbj7hn_51qvfjzj7nx80000gn/T/tmpZyPq5d':
  Duration: 00:00:00.57, bitrate: 213 kb/s
    Stream #0:0: Audio: aac (LC), 4.0, fltp, 213 kb/s
[abuffer @ 0x7f8484d01480] Value inf for parameter 'time_base' out of range [0 - 2.14748e+09]
    Last message repeated 3 times
[abuffer @ 0x7f8484d01480] Error setting option time_base to value 1/0.
[graph 0 input from stream 0:0 @ 0x7f8484d01580] Error applying options to the filter.
Error opening filters!

[jiaaro]

You can manually assign to AudioSegment.converter the path to the binary if you like:

from pydub import AudioSegment
from pydub.utils import which

AudioSegment.converter = which("ffmpeg")

Also… I was able to decode your file using “mp4” as the format:

sound = AudioSegment.from_file("./sensorlog.m4a", format="mp4")

the file does seem to contain AAC audio, but the container format is mpeg4

In [1]: from pydub.utils import mediainfo
In [2]: mediainfo("./sensorlog.m4a")
Out[2]:
{u'DISPOSITION': {u'attached_pic': u'0',
  u'clean_effects': u'0',
  u'comment': u'0',
  u'default': u'1',
  u'dub': u'0',
  u'forced': u'0',
  u'hearing_impaired': u'0',
  u'karaoke': u'0',
  u'lyrics': u'0',
  u'original': u'0',
  u'timed_thumbnails': u'0',
  u'visual_impaired': u'0'},
 u'TAG': {u'com.android.version': u'7.0',
  u'compatible_brands': u'isommp42',
  u'creation_time': u'2017-02-03T20:50:33.000000Z',
  u'handler_name': u'SoundHandle',
  u'language': u'eng',
  u'major_brand': u'mp42',
  u'minor_version': u'0'},
 u'avg_frame_rate': u'0/0',
 u'bit_rate': u'15539',
 u'bits_per_raw_sample': u'N/A',
 u'bits_per_sample': u'0',
 u'channel_layout': u'mono',
 u'channels': u'1',
 u'codec_long_name': u'AAC (Advanced Audio Coding)',
 u'codec_name': u'aac',
 u'codec_tag': u'0x6134706d',
 u'codec_tag_string': u'mp4a',
 u'codec_time_base': u'1/8000',
 u'codec_type': u'audio',
 u'duration': u'7.808000',
 u'duration_ts': u'62464',
 u'filename': u'/Users/jiaaro/Downloads/sensorlog_2017-02-03_12-50-25-345_Dev26c5_Loc27_ActvAppTesting_TypeAUDIO.m4a',
 u'format_long_name': u'QuickTime / MOV',
 u'format_name': u'mov,mp4,m4a,3gp,3g2,mj2',
 u'id': u'N/A',
 u'index': u'0',
 u'max_bit_rate': u'12200',
 u'nb_frames': u'61',
 u'nb_programs': u'0',
 u'nb_read_frames': u'N/A',
 u'nb_read_packets': u'N/A',
 u'nb_streams': u'1',
 u'probe_score': u'100',
 u'profile': u'LC',
 u'r_frame_rate': u'0/0',
 u'sample_fmt': u'fltp',
 u'sample_rate': u'8000',
 u'size': u'15167',
 u'start_pts': u'0',
 u'start_time': u'0.000000',
 u'time_base': u'1/8000'}

[kevinashaw]

Okay, nevermind. Although the project default interpreter had been set properly, the run configuration has overridden the default setting and was using a completely different Python 2.7 instance. Sigh. Well, I learned more about python source and module directories. Thanks again!