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• ffmpeg : -copyts makes -t stop at timestamps, not duration

  30 juillet 2017, par arielCo

  From

  -t duration (input/output)

  When used as an input option (before -i), limit the duration of data read from the input file.

  When used as an output option (before an output url), stop writing the output after its duration reaches duration.

  So this should yield a 1-minute file with timestamps starting at 1:49, right ?

  ffmpeg -y -copyts -ss 1:49 -i ~/Videos/input.mkv -c copy -t 1:00 timing-1m49s.mkv 
  
  ffmpeg version 3.3.2 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 7 (SUSE Linux)
  
    configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --incdir=/usr/include/ffmpeg --extra-cflags='-fmessage-length=0 -grecord-gcc-switches -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -g' --optflags='-fmessage-length=0 -grecord-gcc-switches -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -g' --disable-htmlpages --enable-pic --disable-stripping --enable-shared --disable-static --enable-gpl --disable-openssl --enable-avresample --enable-libcdio --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libcelt --enable-libcdio --enable-libdc1394 --enable-libfreetype --enable-libgsm --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libwebp --enable-netcdf --enable-vaapi --enable-vdpau --enable-libfdk_aac --enable-nonfree --enable-libmp3lame --enable-libtwolame --enable-libx264 --enable-libx265 --enable-libxvid
  
    libavutil      55. 58.100 / 55. 58.100
  
    libavcodec     57. 89.100 / 57. 89.100
  
    libavformat    57. 71.100 / 57. 71.100
  
    libavdevice    57.  6.100 / 57.  6.100
  
    libavfilter     6. 82.100 /  6. 82.100
  
    libavresample   3.  5.  0 /  3.  5.  0
  
    libswscale      4.  6.100 /  4.  6.100
  
    libswresample   2.  7.100 /  2.  7.100
  
    libpostproc    54.  5.100 / 54.  5.100
  
  Input #0, matroska,webm, from '/home/ariel/Videos/input.mkv':
  
    Metadata:
  
      encoder         : libebml v0.7.7 + libmatroska v0.8.0
  
      creation_time   : 2006-07-20T03:07:03.000000Z
  
    Duration: 00:23:57.06, start: 0.000000, bitrate: 1983 kb/s
  
      Stream #0:0: Video: h264 (High), yuv420p(progressive), 720x480, SAR 37:30 DAR 37:20, 29.97 fps, 29.97 tbr, 1k tbn, 59.94 tbc (default)
  
      Stream #0:1(eng): Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s (default)
  
      Stream #0:2(jpn): Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s
  
      Stream #0:3(eng): Subtitle: dvd_subtitle, 720x480 (default)
  
      Metadata:
  
        title           : English Audio
  
      Stream #0:4(eng): Subtitle: dvd_subtitle, 720x480
  
      Metadata:
  
        title           : Japanese Audio
  
  Output #0, matroska, to 'timing-1m49s.mkv':
  
    Metadata:
  
      encoder         : Lavf57.71.100
  
      Stream #0:0: Video: h264 (High) (H264 / 0x34363248), yuv420p(progressive), 720x480 [SAR 37:30 DAR 37:20], q=2-31, 29.97 fps, 29.97 tbr, 1k tbn, 1k tbc (default)
  
      Stream #0:1(eng): Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, fltp, 192 kb/s (default)
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  frame=    0 fps=0.0 q=-1.0 Lsize=       1kB time=00:00:00.00 bitrate=N/A speed=   0x    
  
  video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

  Wrong. It outputs a file with no frames :

  -rwxrwx--- 1 root users 805 Jul 30 01:36 timing-1m49s.mkv

  I have to specify -t 1:49 or more, and e.g. -t 1:55 produces a 6-second file that starts at 0:00 and according to the metadata should last 1:55.

  I arrived at this point trying to extract a clip and add subtitles in the same command, but this minimal case looks to me contrary to the documentation.

• ffmpeg showing "Error initializing output stream 0:0"

  31 juillet 2017, par user2565010

  I am running the following command

  ffmpeg -i DJI_0001.MOV DJI_0001.mp4

  in order to convert the video to mp4 from MOV with no other property changes.

  The issue is that I am getting :

  ffmpeg version N-86863-g2ba20d799a-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 6.4.0 (Debian 6.4.0-2) 20170724
  
    configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gray --enable-libass --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzimg
  
    libavutil      55. 69.100 / 55. 69.100
  
    libavcodec     57.102.100 / 57.102.100
  
    libavformat    57. 76.100 / 57. 76.100
  
    libavdevice    57.  7.100 / 57.  7.100
  
    libavfilter     6. 95.100 /  6. 95.100
  
    libswscale      4.  7.101 /  4.  7.101
  
    libswresample   2.  8.100 /  2.  8.100
  
    libpostproc    54.  6.100 / 54.  6.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'DJI_0001.MOV':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 538182144
  
      compatible_brands: qt  
  
      creation_time   : 2017-07-23T17:04:58.000000Z
  
      location        : 
  
      location-{    : 
  
      comment         : 0.9.142
  
    Duration: 00:00:17.89, start: 0.000000, bitrate: 60017 kb/s
  
      Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 4096x2160 [SAR 1:1 DAR 256:135], 60014 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
  
      Metadata:
  
        creation_time   : 2017-07-23T17:04:58.000000Z
  
        handler_name    : DJI.AVC
  
        encoder         : Dji AVC encoder
  
  File 'DJI_0001.mp4' already exists. Overwrite ? [y/N] y
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  
  Press [q] to stop, [?] for help
  
  [libx264 @ 0x3ed56a0] using SAR=1/1
  
  [libx264 @ 0x3ed56a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
  
  Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
  
  Conversion failed!

  I see no other error message that would indicate an underlying problem. Could anybody please give me some info on how should I fix it ?

• FFMPEG decoding too slow (avcodec_send_packet() / avcodec_receive_frame())

  14 décembre 2022, par Danny

  I'm using ffmpeg libraries to decode, scale, and re-encode video within an MPEG transport stream. I've just recompiled from source to v3.3.2 and changed from the old avcodec_decode_video2() API to the new send/receive API.

  



  Both the old and new APIs decode the video very slowly.

  



  25 fps video = 1 frame every 40ms. However, I see 70 to 120ms per frame to decode. This is a file translator so need it to run faster than real time.

  



  The code outline is below. Anyone have any ideas on how to improve the decoding speed ? There are other posts about the deprecated avcodec_decode_video2() being slow ; none of those were resolved. The new API doesn't run any faster...

  



  gettimeofday(&tv1, NULL);
int rc = av_read_frame(pFormatContext, pESPacket);
gettimeofday(&tv2, NULL);

int ret = avcodec_send_packet(pDecoderContext, pESPacket);
if (ret < 0)
    continue;

ret = avcodec_receive_frame(pDecoderContext, pFrameDec);
if (ret != 0)
{
    printf("avcodec_receive_frame error: %d\n", ret);
    continue;
}
gettimeofday(&tv3, 0);

u_long twoMinusOne   = (tv2.tv_sec - tv1.tv_sec) * 1000000 + tv2.tv_usec - tv1.tv_usec;
u_long threeMinusTwo = (tv3.tv_sec - tv2.tv_sec) * 1000000 + tv3.tv_usec - tv2.tv_usec;

size_t pktSize = mPacketQueue.getTsPktListSize();
printf("  DECODE ReadFrame %lu usec, DecodeVideo %lu usec. mTsPacketList %u items\n", twoMinusOne, threeMinusTwo, pktSize);

transcodeFrame(pFrameDec);

// Scale and re-encode //
-- call avscale to downsample
-- call avcodec_encode_video2() to encode


  



  Some Output

  



  DECODE ReadFrame 6 usec, DecodeVideo 154273 usec.
Dump mpFrameEnc with DateTime: 
  AVFrame Info frame 720 X 406. PTS = 305700353  PKT_PTS = 305700353 Linesize[0]=720. Linesize[1]=360. Linesize[2]=360.   
Time taken to ENCODE video frame = 3685 usec. Scaling time 4 usec

DECODE ReadFrame 8 usec, DecodeVideo 128203 usec.
Time taken to ENCODE video frame = 3724 usec. Scaling time 3 usec

DECODE ReadFrame 8 usec, DecodeVideo 69321 usec.
Time taken to ENCODE video frame = 3577 usec. Scaling time 3 usec


  



  FFMPEG Version

  



  Tests running on core2 duo 3.2 GHz, 32-bit Centos 6.

  



  bin/ffmpeg
ffmpeg version 3.3.2 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11)
  configuration: --prefix=/mnt/swdevel/DVStor/source_build/ext/ffmpeg-build --libdir=/mnt/swdevel/DVStor/source_build/ext/ffmpeg-build/lib3p_build --shlibdir=/mnt/swdevel/DVStor/source_build/ext/ffmpeg-build/lib3p_build --disable-static --enable-shared --disable-cuda --disable-cuvid --disable-nvenc --enable-libx264 --enable-gpl --extra-cflags=-I/usr/local/include/libx264
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
  libpostproc    54.  5.100 / 54.  5.100
Hyper fast Audio and Video encoder