Audio encoding changed, truncated audio files
artisticforge .
artisticforge at gmail.com
Mon Sep 12 13:44:39 PDT 2016
hello
Thank you for the debugging research.
In the verbose log, ffmpeg is seeing a Duration of 36:48 at 1598 Kbps
that is nearly 5 times 320 kbps.
5 times 36:48 gives roughly 10800 seconds or 3hours. 3 hours is what
the file should be.
so for some reason under Debian Linux Jessie the downloaded file is
either corrupted or being read incorrectly.
Testing under MacOSX Mountain Lion with ffmpeg 3.1.3 produces the correct file.
ffmpeg version 3.1.3 Copyright (c) 2000-2016 the FFmpeg developers
built with Apple LLVM version 5.0 (clang-500.2.75) (based on LLVM 3.3svn)
testing under Windows 10 running inside cygwyn produces the correct file.
those results would point to a difference in the Perl installation on
Debian Linux Jessie.
this is why I asked about keeping the downloaded file.
compare across the three different operating systems.
in theory they should be the same.
On Mon, Sep 12, 2016 at 1:37 PM, Vangelis forthnet
<northmedia1 at the.forthnet.gr> wrote:
> On Mon Sep 12 14:24:11 BST 2016, artisticforge . wrote:
>
>> to rule out it being a ffmpeg issue
>> I tried ffmpeg 2.6.7, 2.8.7 & 3.0.2
>> under Debian Linux
>> (snip)
>> The audio downloads are all truncated under Debian Linux
>> I have not tried get_iplayer-2.96 under windows 10
>> (snip)
>> I will post a verbose log file
>> from one of the latest truncated downloads.
>
>
> On Mon Sep 12 16:22:14 BST 2016, artisticforge . wrote:
>
>> the Duration of this program should be close to 3 hours/10800 seconds
>> the Duration of the truncated program is roughly 1/5 of 10800 seconds.
>> (snip)
>> Recording: 420.51MB / 419.43MB 1779kbps 100.3% 00:00:00 remaining
>> INFO: Recorded: 420.75MB in 00:32:17 at 1779kbps to
>> (snip)
>> /Rod_Whiting/Rod_Whiting_-_1362._2016-09-03_p045j35r_original.partial.m4a.m4a
>> INFO: Begin converting file:
>> (snip)
>> ffmpeg version 3.1.3-static http://johnvansickle.com/ffmpeg/
>> (snip)
>> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from
>> '(snip)
>> /Rod_Whiting/Rod_Whiting_-_1362._2016-09-03_p045j35r_original.partial.m4a.m4a':
>> Metadata:
>> major_brand : iso6
>> minor_version : 0
>> compatible_brands: iso6dash
>> Duration: 00:36:48.00, start: 0.000000, bitrate: 1598 kb/s
>> Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo,
>> fltp, 320 kb/s (default)
>> (snip)
>> encoder : Lavf57.41.100
>> (snip)
>> No more output streams to write to, finishing.
>> size= 86656kB time=00:36:48.00 bitrate= 321.5kbits/s speed=1.67e+03x
>
>
> ... I checked your offending PID under my
> Windows Vista SP2 32bit OS, using
> my custom installation of the 2.96 main perl script;
> the version of FFmpeg bundled with the latest
> windows installer is 3.0 (x86), but to approximate
> better your used FFmpeg version (3.1.3), I tried
> the fetch with an FFmpeg 3.1.2 x86 win binary
> kindly provided by "rogerdpack" here:
>
> https://sourceforge.net/projects/ffmpegwindowsbi/files/2016-08-12-v3.1.2/
>
> OT: The Zeranoe repo can't be used anymore
> on Windows XP (last working build is
> ffmpeg-20160227-git-5156578) and Windows Vista
> (last working build is ffmpeg-20160714-git-f41e37b)
> Current releases require Windows 7+.
>
> I was not able to reproduce with FFmpeg 3.1.2;
> command prompt window output follows:
> =====================================
> C:\Program Files\get_iplayer>perl get_iplayer-296w.pl --type=radio
> --pid=p045j35
> r --radiomode=dashhigh1 --force
> get_iplayer 2.96-windows.0, Copyright (C) 2008-2010 Phil Lewis
> This program comes with ABSOLUTELY NO WARRANTY; for details use --warranty.
> This is free software, and you are welcome to redistribute it under certain
> conditions; use --conditions for details.
>
> INFO Trying to stream pid using type radio
> INFO: pid found in cache
> Matches:
> 19240: Rod Whiting - 03/09/2016, BBC Radio Lincolnshire, p045j35r
>
> INFO: 1 Matching Programmes
> INFO: Checking existence of original version
> INFO: dashhigh1 modes will be tried for version original
> INFO: Trying dashhigh1 mode to record radio: Rod Whiting - 1362. 03/09/2016
> INFO: File name prefix = Rod_Whiting_-_1362._2016-09-03_p045j35r_original
>
> INFO: Begin recording file: D:\Vangelis\iPlayer
> Recordings\Rod_Whiting_-_1362._2
> 016-09-03_p045j35r_original.partial.m4a.m4a
> INFO: Recorded: 421.58MB in 00:15:18 at 3762kbps to D:\Vangelis\iPlayer
> Recordi
> ngs\Rod_Whiting_-_1362._2016-09-03_p045j35r_original.partial.m4a.m4a
> INFO: Begin converting file: D:\Vangelis\iPlayer
> Recordings\Rod_Whiting_-_1362._
> 2016-09-03_p045j35r_original.partial.m4a.m4a
> size= 431517kB time=03:03:15.20 bitrate= 321.5kbits/s speed= 682x
> INFO: Converted file: D:\Vangelis\iPlayer
> Recordings\Rod_Whiting_-_1362._2016-09
> -03_p045j35r_original.partial.m4a
> INFO: Recorded file: D:\Vangelis\iPlayer
> Recordings\Rod_Whiting_-_1362._2016-09-
> 03_p045j35r_original.m4a
>
> INFO: MP4 tagging M4A file
>
> Started writing to temp file.
> Progress: =============================================>100%|
> Finished writing to temp file.
> =====================================
>
> MediaInfo excerpt from end file:
>
> File size : 421 MiB
> Duration : 3h 3mn
> Overall bit rate : 322 Kbps
>>
>> (snip)
>
> Writing application : Lavf57.41.100
>
> The file plays fine with a 3hr long duration.
>
> By examining your verbose log, I find that:
> 1. The downloaded file size (using mode
> dashhigh - native perl downloader is used)
> is 420.75MB (partial file before remuxing),
> while in my test it was 421.58MB, i.e. slightly larger.
> 2. When your FFmpeg 3.1.3 is parsing
> the input audio file, it is calculating its duration
> to be 00:36:48.00, which is obviously wrong...
> This partial input file is of the "iso6dash" brand,
> so not a common m4a file that iTunes would
> accept, so that is why a remux to a proper .m4a
> file is mandatory...
> It may be that some stream /container corruption
> is introduced in the downloaded file (hence the
> difference in file sizes between you and me)
> that makes it impossible for FFmpeg to process
> the whole audio stream, just the first 37min of it;
> the end remuxed file of ~ 84Mb is consistent
> with a 320kbps/37min long audio file.
>
> Since I was not able to replicate your issue,
> I fear I am not able to provide further help.
> You've checked other FFmpeg versions on
> your system, but your issue persists; in case
> this is FFmpeg related, you could try
> --radiomode=hafhigh (instead of dashhigh)
> to see how that fares; the partial file in that
> case is in the MPEG-TS type container,
> so perhaps your Debian FFmpeg performs
> better (???).
>
> (And just for accuracy, FFmpeg is not acting as
> an "encoder" in this case, i.e. it does not re-encode
> (change of audio codec), it simply acts as a remuxer,
> it just changes the container the original audio
> stream is packaged in...)
>
> Input from other Debian users could be
> more useful, I guess...
>
>> Is there a way to keep the raw
>> downloaded file before conversion?
>
>
> If by "conversion" you mean the remux to
> the MP4 container (.m4a iTunes compatible
> files), then employ switch "--raw",
> but do consider the constraints mentioned
> previously when that "raw" file comes
> from dash modes
>
> Kind regards,
> Vangelis.
>
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--
terry l. ridder ><>
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