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#1 2010-08-31 11:38:36

benke
Member
Registered: 2010-08-31
Posts: 54

Converting to 3gp with ffmpeg with no sound

Hi all. I checked few topics regarding ffmpeg and 3gp but didn't found the solution for my problem so I am writing new one.

I have some mp4 files. ffmpeg says following info:

Duration: 00:01:13.45, start: 0.000000, bitrate: 870 kb/s
    Stream #0.0(eng): Video: h264, yuv420p, 640x480 [PAR 1:1 DAR 4:3], 741 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16, 125 kb/s

I would like to convert them into 3gp format, h263 video codec and amr audio codec. I am trying to do this with ffmpeg and here's the command I am using:

ffmpeg -i input.mp4 -s qcif -vcodec h263 -r 25 -acodec libopencore_amrnb -ac 1 -ar 8000 -ab 6.7k output.3gp

The problem is that, after the conversion, 3gp file don't have sound. As I know, ac must be 1, ar must be 8000, I tried to play with ab parameter but no improvements. I have some other 3gp files which have good audio. Mplayer does not show any difference between files with good audio and files that don't have audio:

output.3gp
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffh263] vfm: ffmpeg (FFmpeg H.263+)
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 8000 Hz, 1 ch, s16le, 7.2 kbit/5.62% (ratio: 900->16000)
Selected audio codec: [libopencoreamrnb] afm: ffmpeg (AMR Narrowband)
==========================================================================

goodone.3gp
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffh263] vfm: ffmpeg (FFmpeg H.263+)
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 8000 Hz, 1 ch, s16le, 7.2 kbit/5.62% (ratio: 900->16000)
Selected audio codec: [libopencoreamrnb] afm: ffmpeg (AMR Narrowband)
==========================================================================

Anybody have idea how to make working 3gp with h263/amr combination? Any help is appreciated.

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#2 2010-08-31 13:01:28

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

Re: Converting to 3gp with ffmpeg with no sound

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#3 2010-08-31 13:08:20

benke
Member
Registered: 2010-08-31
Posts: 54

Re: Converting to 3gp with ffmpeg with no sound

Anybody already have experience with those 3gp converters from AUR?

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#4 2010-08-31 13:20:27

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

Re: Converting to 3gp with ffmpeg with no sound

I've run your ffmpeg command and I get sound.

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#5 2010-08-31 13:26:25

benke
Member
Registered: 2010-08-31
Posts: 54

Re: Converting to 3gp with ffmpeg with no sound

Can you send me original file? You can cut few seconds...

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#6 2010-08-31 13:28:47

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

Re: Converting to 3gp with ffmpeg with no sound

benke wrote:

Can you send me original file? You can cut few seconds...

I was about to suggest the same, but I'm a noob and I have to goggle how to cut it ;P

[karol@black ~]$ mplayer output.3gp 
MPlayer SVN-r32025-4.5.1 (C) 2000-2010 MPlayer Team
159 audio & 347 video codecs
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing output.3gp.
libavformat file format detected.
[lavf] stream 0: video (h263), -vid 0
[lavf] stream 1: audio (amrnb), -aid 0, -alang eng
VIDEO:  [s263]  176x144  24bpp  25.000 fps  204.0 kbps (24.9 kbyte/s)
Clip info:
 major_brand: 3gp4
 minor_version: 512
 compatible_brands: isomiso23gp4
Opening video filter: [pp=fd]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffh263] vfm: ffmpeg (FFmpeg H.263+)
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 8000 Hz, 1 ch, floatle, 7.2 kbit/2.81% (ratio: 900->32000)
Selected audio codec: [ffamrnb] afm: ffmpeg (AMR Narrowband)
==========================================================================
AO: [alsa] 48000Hz 1ch floatle (4 bytes per sample)
Starting playback...
[PP] Using external postprocessing filter, max q = 6.
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [xv] 176x144 => 256x144 Planar YV12 
A:   2.3 V:   2.3 A-V:  0.000 ct:  0.000   0/  0 11%  2%  1.2% 

Exiting... (Quit)

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#7 2010-08-31 13:31:52

benke
Member
Registered: 2010-08-31
Posts: 54

Re: Converting to 3gp with ffmpeg with no sound

Say

ffmpeg -i input.mp4 -ss 00:00:00 -t 00:00:10 -vcodec copy -acodec copy output.mp4

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#8 2010-08-31 13:58:47

benke
Member
Registered: 2010-08-31
Posts: 54

Re: Converting to 3gp with ffmpeg with no sound

Well, I can convert your input.mp4 file into 3gp file with sound too so it must be some catch with my input files that prevents ffmpeg from making proper 3gp file :-(

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#9 2010-08-31 14:11:39

karol
Archivist
Registered: 2009-05-06
Posts: 25,440

Re: Converting to 3gp with ffmpeg with no sound

I just downloaded that mp4 file from gamespot, so I don't know how was it created.

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