[MEncoder-users] ac3 mistaken for mp3 in recent versions of MEncoder

[Laine Lee]

On 4/27/10 2:17 PM, "Reimar Döffinger" <Reimar.Doeffinger at gmx.de> wrote:

> On Tue, Apr 27, 2010 at 12:18:59PM -0500, Laine Lee wrote:
>> In my latest tested working version, 30677, output contains this:
>> 
>> libavformat file format detected.
>> [ac3 @ 0x101889e00]max_analyze_duration reached
>> [ac3 @ 0x101889e00]Estimating duration from bitrate, this may be inaccurate
>> 
>> With the latest versions (31101, 31097), which don't work, I get this
>> instead:
>> 
>> libavformat file format detected.
>> [mp3 @ 0x101820000]Header missing
>>     Last message repeated 796 times
>> [mp3 @ 0x1018bb600]MAX_READ_SIZE:5000000 reached
>> [mp3 @ 0x1018bb600]Estimating duration from bitrate, this may be inaccurate
>> 
>> Although compiled with identical options within a few minutes of each other
>> on the same system, the newer versions apparently think my .ac3 is .mp3. Any
>> idea why?
> 
> A sample file would be useful.
> Testing with FFmpeg and it also misdetects it reporting it to them would be
> a good idea, too.
> In any case, the very least would be a more complete output, normally that
> means
> the full output, also using -v, and at most leaving things out when there are
> really hundreds of lines of the same thing.
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Thanks, Reimar.

First, the latest ffmpeg works fine for similar conversions, in fact it
provides a workaround. If I use -nosound instead of the reference to the ac3
file I want to copy and specify an m2v file for output as well, I can mux
the resulting video file with the ac3 file I was trying to copy with
MEncoder using an ffmpeg command like this:

ffmpeg -y -i adujsted.m2v -i adjusted.ac3 -acodec copy -target film-dvd -s
720x480 -sameq  -aspect 16:9 -minrate 6600k -b 9000k  -bufsize 4096k mux.mpg

Anyway, here's a zip file (under 83M) containing everything suggested by you
in your reply, as well as the complete command line used to produce the
results described in my OP (above). If you have encoding options to suggest,
especially to decrease blockiness and noise in passages that have low
luminance and contrast, please feel free to do that, too.

https://rowdyspace.utsa.edu/users/mek985/share/Target/flyClip.zip

On a humorous note, while I was preparing this response, the problem was
apparently remedied between mplayer versions 31101 and 31103. So please have
pity and take a look to offer suggestions for improved quality.

Thanks again!

Laine Lee