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• ffmpeg : Resampling with input channels greater than 2 unsupported ?

  13 septembre 2011, par user739711

  This question is already been asked but because that thread is old I am posting again.

  When a video file has 5.1 audio channels ffmpeg is not able to convert it to another format giving error:

  "Resampling with input channels greater than 2 unsupported"

  I saw some blogs saying I can modify the code and or patch ffmpeg for it.

  Any solution found yet?

• How to play random part of mp4 file with vlc or something else ?

  13 septembre 2011, par pprzemek

  I have random part (99,9% somewhere in the middle) of the mp4 file. Problem is that it's not in any container or anything just a binary piece of the file in random offset and send to me... it will keep growing but it'll take a while and I need to play content right away.

  I can get all necessary metadata information for that file from other source before I even start receiving those binary data, but:

  1. How to do this? I mean what headers do I need and how to get them? and
  2. How to later tell vlc (or maybe some other player) that this moov atom (or some other data) that it should use for this part of the file and start playing it?

• How to play video file with 720x480 and 60fps on ipad using ffmpeg

  12 septembre 2011, par akash

  I can play video files with 320x180 resolution on ipad but files with more than 320x180 and 60fps are playing slowly. anybody can tell what will be the issue.?

  is iOS supports playback of files with 60fps?

  Regards NewBee

• ffmpeg link errors when building on iPhone 4.3 SDK

  12 septembre 2011, par YuzaKen

  After a rather trying few days, I finally got ffmpeg to compile under Xcode 4 with SDK 4.3. The issue no is a series (39) link errors. They fall into at least two cases: assembly language routines and static arrays defined in header files. My believe is that it is generating C method names for the assembly routines while the .c files containing the reference to the routine is generating a different method name (munging).

  Undefined symbols for architecture armv7:

    "_ff_vector_fmul_vfp", referenced from:
        _ff_dsputil_init_vfp in libavcodec.a(dsputil_init_vfp.o)
    "_main", referenced from:
        start in crt1.3.1.o
    "_av_solve_lls", referenced from:
        _ff_lpc_calc_coefs in libavcodec.a(lpc.o)
    "_ff_inv_aanscales", referenced from:
        _dct_quantize_trellis_c in libavcodec.a(mpegvideo_enc.o)
        _decode_frame in libavcodec.a(eamad.o)
        _tgq_decode_frame in libavcodec.a(eatgq.o)
        _tqi_decode_frame in libavcodec.a(eatqi.o)
    "_ff_add_pixels_clamped_armv6", referenced from:
        _ff_dsputil_init_armv6 in libavcodec.a(dsputil_init_armv6.o)
    "_ff_cga_palette", referenced from:
        _tmv_decode_frame in libavcodec.a(tmv.o)
    "_ff_svq1_inter_multistage_vlc", referenced from:
        _encode_block in libavcodec.a(svq1enc.o)
        _svq1_decode_init in libavcodec.a(svq1dec.o)
    "_ff_simple_idct_armv6", referenced from:
        _ff_dsputil_init_armv6 in libavcodec.a(dsputil_init_armv6.o)
    "_BZ2_bzDecompressInit", referenced from:
        _matroska_decode_buffer in libavformat.a(matroskadec.o)
    "_ff_put_pixels8_y2_arm", referenced from:
        _ff_put_pixels16_y2_arm in libavcodec.a(dsputil_init_arm.o)
        _dsputil_init_arm in libavcodec.a(dsputil_init_arm.o)
    "_ff_simple_idct_add_armv6", referenced from:
  

  ...and so on.

  Anyone with experience with ffmpeg on iPhone? Successfully?

• How to tell if ffmpeg errored ?

  12 septembre 2011, par Eric

  The Situation:
  I'm using ffmpeg (via php) to convert video files. I configured my convert script to return the output (as the $error array) from the exec() command. My assumption was that if no error occurred, $error would be an empty array.

  The Problem:
  The problem is that, the script returns output even if there was no error in conversion. (I can tell that there was no error because a playable video file is output.)

  The Question:
  How does ffmpeg format its errors/output? I want to be able to parse this and determine if an error occurred and what error it was.

  Thanks!

  Code:
  *An example of a non-error output:

  FFmpeg version git-N-29201-g37c0a44, Copyright (c) 2000-2011 the FFmpeg developers|  built on Sep  9 2011 23:29:21 with gcc 4.1.2 20080704 (Red Hat 4.1.2-50)|  configuration: --prefix=/usr/local/hgffmpeg --enable-shared --enable-nonfree --enable-avfilter --enable-filter=movie --enable-gpl --enable-pthreads --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfaac --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --extra-cflags=-I/usr/local/hgffmpeg/include/ --extra-ldflags=-L/usr/local/hgffmpeg/lib --enable-decoder=ac3 --enable-decoder=asv1 --enable-decoder=asv2 --enable-decoder=flac --enable-decoder=wmv1 --enable-decoder=wmv2 --enable-decoder=wmv3 --enable-decoder=mpeg1video --enable-decoder=mpeg2video --enable-decoder=flv --enable-decoder=fraps --enable-decoder=h263 --enable-decoder=h264 --enable-decoder=libgsm --enable-decoder=mjpeg --enable-decoder=mpeg4 --enable-decoder=mpeg4aac --enable-decoder=mpegvideo --enable-decoder=mpeg4aac --enable-decoder=msmpeg4v1 --enable-decoder=msmpeg4v2 --enable-decoder=msmpeg4v3 --enable-decoder=pcm_alaw --enable-decoder=pcm_mulaw --enable-encoder=ac3 --enable-encoder=asv1 --enable-encoder=asv2 --enable-encoder=flac --enable-encoder=h263 --enable-encoder=flashsv --enable-encoder=flv --enable-encoder=libgsm --enable-encoder=mjpeg --enable-encoder=msmpeg4v3 --enable-encoder=pcm_alaw --enable-encoder=pcm_mulaw --enable-encoder=mpeg1video --enable-encoder=mpeg2video --enable-encoder=mpeg4 --enable-encoder=msmpeg4v1 --enable-encoder=msmpeg4v2 --enable-encoder=rv10 --enable-encoder=rv20 --enable-encoder=vorbis --enable-encoder=wmav1 --enable-encoder=wmav2 --enable-encoder=wmv1 --enable-encoder=wmv2 --disable-demuxer=v4l --disable-demuxer=v4l2 --enable-version3|  libavutil    50. 40. 1 / 50. 40. 1|  libavcodec   52.120. 0 / 52.120. 0|  libavformat  52.108. 0 / 52.108. 0|  libavdevice  52.  4. 0 / 52.  4. 0|  libavfilter   1. 79. 1 /  1. 79. 1|  libswscale    0. 13. 0 /  0. 13. 0|[mpeg1video @ 0x1f6d030] skipped MB in I frame at 5 0|[mpeg1video @ 0x1f6d030] Warning MVs not available|[mpeg1video @ 0x1f6d030] concealing 260 DC, 260 AC, 260 MV errors|[mpegvideo @ 0x1f6a660] Estimating duration from bitrate, this may be inaccurate|Input #0, mpegvideo, from '../uploads/test_vid/unencodedVideo.mpg':|  Duration: 00:00:00.01, bitrate: 104860 kb/s|    Stream #0.0: Video: mpeg1video, yuv420p, 320x200 [PAR 1:1 DAR 8:5], 104857 kb/s, 23.98 fps, 23.98 tbr, 1200k tbn, 23.98 tbc|WARNING: The bitrate parameter is set too low. It takes bits/s as argument, not kbits/s|File '../uploads/test_vid/video.flv' already exists. Overwrite ? [y/N] Not overwriting - exiting