[clug] problem with 'lame'?

[Bob Edwards]

On 17/09/14 10:21, Eyal Lebedinsky wrote:
> I wonder if anyone can explain the problem I had. I now do not use this
> method (I do ffmpeg) but still
> want to understand why it was failing.

Hi Eyal,

I haven't done this sort of stuff for some years, but I notice your
script is invoking mplayer with "-really-quiet". Maybe try running
mplayer without "-really-quiet" and see if it is trying to tell you
something significant about the file it is generating?

Cheers,

Bob Edwards.

>
> I was transcoding podcasts (music programs) for many years with a simple
> script.
> This was the way of converting everything to pcm upfront (mplayer) then
> encode as mp3 (lame).
>
> This worked fine until some time ago (first short one was Aug a year
> ago) when it started truncating files.
> This was consistent, with exactly the same truncation every time. Below
> is an example.
>
> (1) Note the original length 2:05:04.0
> (2) Then note how lame *starts* with a length of 1:41:21
> (3) The result says 1:41:27.0
> (4) Finally note that capturing the pcm shows it is not truncated.
>
>
> ===== test.sh
> prog="my_program"
> pipe="$HOME/tmp/xxx"
> mknod "$pipe" p
> mplayer -really-quiet -nolirc -nojoystick -vo null -vc null -ao
> pcm:fast:waveheader:file="$pipe" $prog.m4a &
> lame "$pipe" $prog.mp3
> rm "$pipe"
> =====
>
>
> ===== (1) play the original
> $ mplayer my_program.m4a
> MPlayer SVN-r36171-4.8.1 (C) 2000-2013 MPlayer Team
>
> Playing my_program.m4a.
> libavformat version 54.63.104 (external)
> libavformat file format detected.
> [lavf] stream 0: audio (aac), -aid 0, -alang und
> Clip info:
>   major_brand: mp42
>   minor_version: 0
>   compatible_brands: M4A mp42isom
>   creation_time: 2014-09-13 01:07:19
>   encoder: Nero AAC codec / 1.5.4.0
> Load subtitles in ./
> ==========================================================================
> Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
> libavcodec version 54.92.100 (external)
> AUDIO: 44100 Hz, 2 ch, floatle, 64.0 kbit/2.27% (ratio: 7999->352800)
> Selected audio codec: [ffaac] afm: ffmpeg (FFmpeg AAC (MPEG-2/MPEG-4
> Audio))
> ==========================================================================
> AO: [pulse] 44100Hz 2ch floatle (4 bytes per sample)
> Video: no video
> Starting playback...
> A:   1.2 (01.2) of 7504.0 ( 2:05:04.0)  0.5%             <<<<<<<<<<
> =====
>
> ===== (2) transcode$ sh test.sh
> $ sh test.sh
> LAME 3.99.5 64bits (http://lame.sf.net)
> Using polyphase lowpass filter, transition band: 16538 Hz - 17071 Hz
> Encoding /home/eyal/tmp/xxx to my_program.mp3
> Encoding as 44.1 kHz j-stereo MPEG-1 Layer III (11x) 128 kbps qval=3
>      Frame          |  CPU time/estim | REAL time/estim | play/CPU |    ETA
>     200/233018 ( 0%)|    0:00/    5:26|    0:00/    5:28|   18.659x|
> 5:28
> -1:41:21-------------------------------------------------------
> <<<<<<<<<<
>    128.0       23.0  77.0        98.5   0.5   1.0^C
> =====
>
>
> ===== (3) play the result
> $ mplayer my_program.mp3
> MPlayer SVN-r36171-4.8.1 (C) 2000-2013 MPlayer Team
>
> Playing my_program.mp3.
> libavformat version 54.63.104 (external)
> Audio only file format detected.
> Load subtitles in ./
> ==========================================================================
> Opening audio decoder: [mpg123] MPEG 1.0/2.0/2.5 layers I, II, III
> AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 16000->176400)
> Selected audio codec: [mpg123] afm: mpg123 (MPEG 1.0/2.0/2.5 layers I,
> II, III)
> ==========================================================================
> AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample)
> Video: no video
> Starting playback...
> A:   0.4 (00.4) of 6087.0 ( 1:41:27.0)  0.3%            <<<<<<<<<<
> =====
>
> ===== (4) check the pcm
> $ mplayer -really-quiet -nolirc -nojoystick -vo null -vc null -ao
> pcm:fast:waveheader:file=my_program.pcm my_program.m4a
> $ mplayer my_program.pcm
> MPlayer SVN-r36171-4.8.1 (C) 2000-2013 MPlayer Team
>
> Playing my_program.pcm.
> libavformat version 54.63.104 (external)
> Audio only file format detected.
> Load subtitles in ./
> ==========================================================================
> Opening audio decoder: [pcm] Uncompressed PCM audio decoder
> AUDIO: 44100 Hz, 2 ch, floatle, 2822.4 kbit/100.00% (ratio: 352800->352800)
> Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
> ==========================================================================
> AO: [pulse] 44100Hz 2ch floatle (4 bytes per sample)
> Video: no video
> Starting playback...
> A:   0.7 (00.6) of 7504.0 ( 2:05:04.0)  0.0%            <<<<<<<<<<
> =====
>