[FFmpeg-user] Use concat demuxer with input format

[Hans Carlson]

Is it possible to use the concat demuxer with an input format?

For example:

   $ ffmpeg -f s16le -ac 2 -f concat -i concat-raw.txt ...
or
   $ ffmpeg -f concat -f s16le -ac 2 -i concat-raw.txt ...

I've tried both and it doesn't work, so I assume it's either not supported 
or I'm doing something wrong.

To back up a little, I'm trying to concat parts of several PCM files. 
Since they're PCM files, I need to supply the format as an input arg. 
And because I only want parts from each file, I want to use the concat 
demuxer along with the inpoint, outpoint options.  For example, given the 
following:

   $ ffmpeg -f s16le -ac 2 -i file1.raw
   ffmpeg version N-86775-gd0ba0be Copyright (c) 2000-2017 the FFmpeg developers
     built with gcc 4.9.2 (GCC) 20150212 (Red Hat 4.9.2-6)
     configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
     libavutil      55. 67.100 / 55. 67.100
     libavcodec     57.100.104 / 57.100.104
     libavformat    57. 75.100 / 57. 75.100
     libavdevice    57.  7.100 / 57.  7.100
     libavfilter     6. 95.100 /  6. 95.100
     libswscale      4.  7.101 /  4.  7.101
     libswresample   2.  8.100 /  2.  8.100
     libpostproc    54.  6.100 / 54.  6.100
   [s16le @ 0x3d9a420] Estimating duration from bitrate, this may be inaccurate
   Guessed Channel Layout for Input Stream #0.0 : stereo
   Input #0, s16le, from 'file1.raw':
     Duration: 00:05:00.00, bitrate: 1411 kb/s
       Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
   At least one output file must be specified

   $ ffmpeg -hide_banner -f s16le -ac 2 -i file2.raw
   [s16le @ 0x22ed440] Estimating duration from bitrate, this may be inaccurate
   Guessed Channel Layout for Input Stream #0.0 : stereo
   Input #0, s16le, from 'file2.raw':
     Duration: 00:03:00.00, bitrate: 1411 kb/s
       Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
   At least one output file must be specified

   $ cat concat-raw.txt
   file file1.raw
   inpoint 30
   outpoint 270
   duration 300

   file file2.raw
   inpoint 10
   outpoint 160
   duration 180

And trying the 2 commands listed at the top:

   $ ffmpeg -hide_banner -f s16le -ac 2 -f concat -i concat-raw.txt -codec mp3 test-1.mp3
   [adp @ 0x226d7a0] Format adp detected only with low score of 25, misdetection possible!
   concat-raw.txt: Operation not permitted

   $ ffmpeg -hide_banner -f concat -f s16le -ac 2 -i concat-raw.txt -codec mp3 test-2.mp3
   [s16le @ 0x3ba2540] Estimating duration from bitrate, this may be inaccurate
   Guessed Channel Layout for Input Stream #0.0 : stereo
   Input #0, s16le, from 'concat-raw.txt':
     Duration: 00:00:00.00, bitrate: 1423 kb/s
       Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
   Stream mapping:
     Stream #0:0 -> #0:0 (pcm_s16le (native) -> mp3 (libmp3lame))
   Press [q] to stop, [?] for help
   [pcm_s16le @ 0x3bac280] Multiple frames in a packet.
   [pcm_s16le @ 0x3bac280] Invalid PCM packet, data has size 1 but at least a size of 4 was expected
   Error while decoding stream #0:0: Invalid data found when processing input
   Output #0, mp3, to 'test-2.mp3':
     Metadata:
       TSSE            : Lavf57.75.100
       Stream #0:0: Audio: mp3 (libmp3lame), 44100 Hz, stereo, s16p
       Metadata:
         encoder         : Lavc57.100.104 libmp3lame
   [libmp3lame @ 0x3bb0200] Trying to remove 1152 samples, but the queue is empty
   size=       1kB time=00:00:00.02 bitrate= 320.1kbits/s speed=6.76x
   video:0kB audio:1kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 30.299400%

And... just to prove both files work fine on their own:

   $ ffmpeg -hide_banner -f s16le -ac 2 -i file1.raw -codec mp3 file1.mp3
   [s16le @ 0x3df9580] Estimating duration from bitrate, this may be inaccurate
   Guessed Channel Layout for Input Stream #0.0 : stereo
   Input #0, s16le, from 'file1.raw':
     Duration: 00:05:00.00, bitrate: 1411 kb/s
       Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
   Stream mapping:
     Stream #0:0 -> #0:0 (pcm_s16le (native) -> mp3 (libmp3lame))
   Press [q] to stop, [?] for help
   Output #0, mp3, to 'file1.mp3':
     Metadata:
       TSSE            : Lavf57.75.100
       Stream #0:0: Audio: mp3 (libmp3lame), 44100 Hz, stereo, s16p
       Metadata:
         encoder         : Lavc57.100.104 libmp3lame
   size=    4688kB time=00:05:00.01 bitrate= 128.0kbits/s speed=59.6x
   video:0kB audio:4688kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.005270%

   $ ffmpeg -hide_banner -f s16le -ac 2 -i file2.raw -codec mp3 file2.mp3
   [s16le @ 0x2912580] Estimating duration from bitrate, this may be inaccurate
   Guessed Channel Layout for Input Stream #0.0 : stereo
   Input #0, s16le, from 'file2.raw':
     Duration: 00:03:00.00, bitrate: 1411 kb/s
       Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
   Stream mapping:
     Stream #0:0 -> #0:0 (pcm_s16le (native) -> mp3 (libmp3lame))
   Press [q] to stop, [?] for help
   Output #0, mp3, to 'file2.mp3':
     Metadata:
       TSSE            : Lavf57.75.100
       Stream #0:0: Audio: mp3 (libmp3lame), 44100 Hz, stereo, s16p
       Metadata:
         encoder         : Lavc57.100.104 libmp3lame
   size=    2813kB time=00:03:00.01 bitrate= 128.0kbits/s speed=57.9x
   video:0kB audio:2813kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.008783%

So, is it just not possible to use an INPUT format option (-f s16le) AND 
the concat demuxer?

If so, do I have to convert each file to mp3 first and then use concat or 
is there another way to do what I'm want without creating intermediate 
files?