HOWTO: Install and use the latest FFmpeg and x264

[daaxix]

I compiled exactly as in the first post for 10.04, then ran the following command :

ffmpeg -i ./input.mkv -s 480x320 -vcodec mpeg4 -acodec libfaac -ac 1 -ar 16000 -r 13 -ab 32000 -aspect 3:2 output.mp4

To attempt to transcode for my G1 Android phone.

This results in the following output :

[scale @ 0x2b28930] w:720 h:480 fmt:yuv420p -> w:480 h:320 fmt:yuv420p flags:0xa0000004
Output #0, mp4, to 'outut.mp4':
  Metadata:
    encoder         : Lavf52.74.0
    Stream #0.0: Video: mpeg4, yuv420p, 480x320 [PAR 1:1 DAR 3:2], q=2-31, 200 kb/s, 13 tbn, 13 tbc
    Stream #0.1(eng): Audio: libfaac, 16000 Hz, 1 channels, s16, 32 kb/s
    Metadata:
      title           : 6ch NDAAC
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
[aac @ 0x2aeade0] Duplicate channel tag found, attempting to remap.
Resampling with input channels greater than 2 unsupported.
Can not resample 6 channels @ 48000 Hz to 1 channels @ 16000 Hz

but works just fine if I leave out the

-ac 1 -ar 16000

switches, but unfortunately will then not play on my G1. The G1 is very fickle.

Any suggestions?

[Bachstelze]

I compiled exactly as in the first post for 10.04, then ran the following command :

ffmpeg -i ./input.mkv -s 480x320 -vcodec mpeg4 -acodec libfaac -ac 1 -ar 16000 -r 13 -ab 32000 -aspect 3:2 output.mp4

To attempt to transcode for my G1 Android phone.

This results in the following output :

[scale @ 0x2b28930] w:720 h:480 fmt:yuv420p -> w:480 h:320 fmt:yuv420p flags:0xa0000004
Output #0, mp4, to 'outut.mp4':
  Metadata:
    encoder         : Lavf52.74.0
    Stream #0.0: Video: mpeg4, yuv420p, 480x320 [PAR 1:1 DAR 3:2], q=2-31, 200 kb/s, 13 tbn, 13 tbc
    Stream #0.1(eng): Audio: libfaac, 16000 Hz, 1 channels, s16, 32 kb/s
    Metadata:
      title           : 6ch NDAAC
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
[aac @ 0x2aeade0] Duplicate channel tag found, attempting to remap.
Resampling with input channels greater than 2 unsupported.
Can not resample 6 channels @ 48000 Hz to 1 channels @ 16000 Hz

but works just fine if I leave out the

-ac 1 -ar 16000

switches, but unfortunately will then not play on my G1. The G1 is very fickle.

Any suggestions?

Since ffmpeg apparently has problems subsampling your 5.1 audio to Mono, I'd try to process the sound separately with other tools. Which format is it in?

[daaxix]

Since ffmpeg apparently has problems subsampling your 5.1 audio to Mono, I'd try to process the sound separately with other tools. Which format is it in?

The audio is MPEG-4 AAC.

Thanks, I <3 Ubuntu Forums!

[HHelsinger]

When I try to transcode using ffmpeg & libx264, I get the error "unknown encoder libx264" I've followed the threads, and reinstalled and updated libx264.

I've configured the latest ffmpeg (carefully following the instructions) with

--enable-nonfree --enable-libfaac --enable-gpl --enable-libx264

After configuring, it reports that both libfaac and libx264 are enabled.
But when I compile I get this error:

/usr/local/src/ffmpeg-export-2010-07-11/libavcodec/libavcodec.a(libx264.o): In function `X264_init':
/usr/local/src/ffmpeg-export-2010-07-11/libavcodec/libx264.c:300: undefined reference to `x264_encoder_open_102'
collect2: ld returned 1 exit status
make: *** [ffmpeg_g] Error 1

and indeed, here is the code from line 300 of libx264.c

if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER)
x4->params.b_repeat_headers = 0;

x4->enc = x264_encoder_open(&x4->params);

So at this point I am way in over my head, and going under for the third time.

I'm trying to convert Cinelerra output for Vimeo. Anyone have any suggestions for alternative encodings that don't call libx264?

Thanks.

[qyot27]

The audio is MPEG-4 AAC.

Thanks, I <3 Ubuntu Forums!

Assuming that the audio is the second track in the file:

mkvextract tracks input.mkv 2:input.aac
faad input.aac -o output.wav

Open the .wav in Audacity and merge the channels down to mono. Then either swap out the audio from the original using MKVToolNix (and use this new file to do the conversion) or find a way to point ffmpeg at the new audio file while disabling the original file's audio.

[prupert]

Can you not transcode to a file with two audio channels and then to a file with one?

[dannyboy79]

When I try to transcode using ffmpeg & libx264, I get the error "unknown encoder libx264" I've followed the threads, and reinstalled and updated libx264.

I've configured the latest ffmpeg (carefully following the instructions) with

After configuring, it reports that both libfaac and libx264 are enabled.
But when I compile I get this error:


and indeed, here is the code from line 300 of libx264.c

So at this point I am way in over my head, and going under for the third time.

I'm trying to convert Cinelerra output for Vimeo. Anyone have any suggestions for alternative encodings that don't call libx264?

Thanks.

i've had no problems at all using this google bash script to compile ffmpeg (svn) and x264 (git).
http://code.google.com/p/x264-ffmpeg-up-to-date/

[prupert]

i've had no problems at all using this google bash script to compile ffmpeg (svn) and x264 (git).
http://code.google.com/p/x264-ffmpeg-up-to-date/

The script (that I wrote) basically does exactly what is listed in this HowTo, it just does it all automatically.

So, yeah, try it and see if it works for you, if it does, then you musta followed one of the instructions wrong somewhere...

[n.hinton]

Hi prupert,

You beat me to it! I wouldn't run a script without at least having a glance through it, and if I learned nothing else from reading, at least I would have learned enough to credit yourself and FakeOutdoorsman for the script. Google script indeed!

[FakeOutdoorsman]

Hi flyone,



I love fiddling with these things:

svn info | sed '5!d' | awk '{ print $NF }'

Would always work unless the number of lines changed, reasonably unlikely... A variation:

svn info | sed -e '5!d' -e 's/^.\{10\}//'

Andrew

I'm not very good at fiddling at these things (just look at that ugly x264 pkgversion). Much more useful. Adopting. Thanks, Andrew!

When I try to transcode using ffmpeg & libx264, I get the error "unknown encoder libx264" I've followed the threads, and reinstalled and updated libx264.

I've configured the latest ffmpeg (carefully following the instructions) with

After configuring, it reports that both libfaac and libx264 are enabled.
But when I compile I get this error:


and indeed, here is the code from line 300 of libx264.c

So at this point I am way in over my head, and going under for the third time.

I'm trying to convert Cinelerra output for Vimeo. Anyone have any suggestions for alternative encodings that don't call libx264?

Thanks.

My guess is that you still have an old x264 on your system. Try removing any x264 packages including libx264-dev and then continue with the Updating FFmpeg and x264 section of the guide.