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• ffmpeg cannot generate thumbnail

  8 mai 2018, par rabbit

  In Windows to make a thumbnail with ffmpeg I use :

  ./ffmpeg -i 1.mp4 -ss 00:00:01 -f image2 1.jpg

  or :

  ./ffmpeg -ss 00:00:01 -i 1.mp4 -f image2 1.jpg

  But none can generate a thumbnail, it displays :

  ffmpeg -i input.mp4 -ss 1 -frames:v 1 output.jpg
  
  ffmpeg version N-91013-g8007a86363 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with gcc 7.3.1 (GCC) 20180406
  
    configuration: 
  
    libavutil      56. 18.100 / 56. 18.100
  
    libavcodec     58. 19.101 / 58. 19.101
  
    libavformat    58. 13.102 / 58. 13.102
  
    libavdevice    58.  4.100 / 58.  4.100
  
    libavfilter     7. 21.100 /  7. 21.100
  
    libswscale      5.  2.100 /  5.  2.100
  
    libswresample   3.  2.100 /  3.  2.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 1
  
      compatible_brands: isom
  
      creation_time   : 2017-01-11T08:30:55.000000Z
  
      encoder         : My MP4Box GUI 0.6.0.6 /my-mp4box-gui.zymichost.com>
  
    Duration: 00:03:27.93, start: 0.000000, bitrate: 9345 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 2560x1440 [SAR 1:1 DAR 16:9], 9216 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc (default)
  
      Metadata:
  
        creation_time   : 2016-10-14T14:16:02.000000Z
  
        handler_name    : videoplayback.mp4
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 125 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-01-11T08:30:56.000000Z
  
        handler_name    : videoplayback (1).m4a
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> mjpeg (native))
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x55ad99ffe1c0] deprecated pixel format used, make sure you did set range correctly
  
  Output #0, image2, to 'output.jpg':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 1
  
      compatible_brands: isom
  
      encoder         : Lavf58.13.102
  
      Stream #0:0(und): Video: mjpeg, yuvj420p(pc), 2560x1440 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 30 fps, 30 tbn, 30 tbc (default)
  
      Metadata:
  
        creation_time   : 2016-10-14T14:16:02.000000Z
  
        handler_name    : videoplayback.mp4
  
        encoder         : Lavc58.19.101 mjpeg
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
  
  frame=    0 fps=0.0 q=0.0 Lsize=N/A 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
  
  Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)

  and I find that the video which encoder is

   My MP4Box GUI 0.6.0.6 /my-mp4box-gui.zymichost.com>

  the ffmpeg cannot generate thumbnail. And how can I generate the thumbnail ?

• 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


  


• 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 ?