Recherche avancée

Sur d’autres sites (6298)

• aacenc_pred : rework the way prediction is done

  29 août 2015, par Rostislav Pehlivanov

  aacenc_pred : rework the way prediction is done
  This commit completely alters the algorithm of prediction.
  
  The original commit which introduced prediction was completely
  
  incorrect to even remotely care about what the actual coefficients
  
  contain or whether any options were enabled. Not my actual fault.
  This commit treats prediction the way the decoder does and expects
  
  to do : like lossy encryption. Everything related to prediction now
  
  happens at the very end but just before quantization and encoding
  
  of coefficients. On the decoder side, prediction happens before
  
  anything has had a chance to even access the coefficients.
  Also the original implementation had problems because it actually
  
  touched the band_type of special bands which already had their
  
  scalefactor indices marked and it’s a wonder the asserion wasn’t
  
  triggered when transmitting those.
  Overall, this now drastically increases audio quality and you should
  
  think about enabling it if you don’t plan on playing anything encoded
  
  on really old low power ultra-embedded devices since they might not
  
  support decoding of prediction or AAC-Main. Though the specifications
  
  were written ages ago and as times change so do the FLOPS.
  Signed-off-by : Rostislav Pehlivanov <atomnuker@gmail.com>
  

  • [DH] libavcodec/aac.h
  • [DH] libavcodec/aaccoder.c
  • [DH] libavcodec/aacenc.c
  • [DH] libavcodec/aacenc.h
  • [DH] libavcodec/aacenc_pred.c
  • [DH] libavcodec/aacenc_pred.h

• Correct recording time of the first frame of a video

  27 juillet 2017, par Vítor Cézar

  How do I get the correct time of the first frame recorded on a video ? I executed the command

  ffprobe -v error -show_streams [file_path]

  and got these values of timecode and creation time for the first stream :

  TAG:creation_time=2017-07-26T16:48:10.000000Z
  
  TAG:language=eng
  
  TAG:handler_name=   GoPro AVC
  
  TAG:encoder=GoPro AVC encoder
  
  TAG:timecode=17:21:54:28

  The problem is that the video started being recorded on 16:48:11:504 and neither timecode nor creation time shows this value. If possible I need the precision on milliseconds.

• WebM live streaming via DASH

  4 juin 2018, par ewack

  I am following the instructions here to try to make WebM live streaming via DASH. My input is from an Axis camera and it is streaming as h264 encoding. I am using node to spin up the ffmpeg processes. I am able to create the .hdr file and the .chk files. The .mpd file is even created but it’s empty and I get an error saying :

  Could not write header for output file #0 (incorrect codec parameters ?): Operation not permittedStream mapping: Stream #0:0 -> #0:0 (copy)

  Here’s all of my code :

  var express = require('express');
  
  spawn = require('child_process').spawn;
  
  
  
  var app = express();
  
  
  
  app.use(express.static(__dirname + '/public'));
  
  
  
  app.listen(8080);
  
  console.log("Running on Port 8080");
  
  
  
  var ffmpeg1 = spawn('ffmpeg', [
  
      '-y',
  
      //video
  
      '-i', 'rtsp://admin:password@192.168.1.54:554/axis-media/media.amp?videocodec=h264&resolution=1280x720',
  
  
  
      '-map', '0:0',
  
      '-pix_fmt', 'yuv420p',
  
      '-color_range', '2',
  
      '-c:v', 'libvpx-vp9',
  
  
  
      '-s', '1280x720',
  
      '-keyint_min', '25',
  
      '-g', '25', 
  
  
  
      // //VP9_LIVE_PARAMS
  
      '-speed', '6', 
  
      '-tile-columns', '4',
  
      '-frame-parallel', '1', 
  
      '-threads', '8', 
  
      '-static-thresh', '0', 
  
      '-max-intra-rate', '300',
  
      '-deadline', 'realtime', 
  
      '-lag-in-frames', '0',
  
      '-error-resilient', '1',
  
  
  
      '-f', 'webm_chunk',
  
      '-header', 'public/glass_360.hdr',
  
      '-chunk_start_index', '1',
  
      'public/glass_360_%d.chk',
  
  ]);
  
  
  
  
  
  setTimeout(()=> {
  
    var ffmpeg2 = spawn('ffmpeg', [
  
      '-y',
  
      '-f', 'webm_dash_manifest',
  
      '-live', '1',
  
      '-i', 'public/glass_360.hdr',
  
      '-c', 'copy',
  
      '-map', '0',
  
      '-r', '25',
  
      '-framerate', '25',
  
  
  
      '-f', 'webm_dash_manifest',
  
      '-live', '1',
  
  
  
      '-adaptation_sets', '"id=0,streams=0"',
  
      '-chunk_start_index', '1',
  
      '-chunk_duration_ms', '2000',
  
      '-time_shift_buffer_depth', '7200',
  
      '-minimum_update_period', '7200',
  
  
  
      'public/glass_live_manifest.mpd'
  
    ]);
  
    ffmpeg2.stdout.on('data', 
  
        function (data) {
  
            console.log('ff2std: ' + data);
  
        }
  
    );
  
  
  
    ffmpeg2.stderr.on('data', 
  
        function (data) {
  
            console.log('ff2err: ' + data);
  
        }
  
    );
  
  }, 5000);
  
  
  
  ffmpeg1.stdout.on('data', 
  
      function (data) {
  
          console.log('ff1std: ' + data);
  
      }
  
  );
  
  
  
  ffmpeg1.stderr.on('data', 
  
      function (data) {
  
          console.log('ff1err: ' + data);
  
      }
  
  );

  Here is all of my output :

  Running on Port 8080
  
  ff1err: ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.1.2/include/openjpeg-2.1 --enable-nonfree --enable-vda
  
  
  
  ff1err:   libavutil      55. 34.101 / 55. 34.101
  
    libavcodec     57. 64.101 / 57. 64.101
  
    libavformat    57. 56.101 / 57. 56.101
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libavresample   3.  1.  0 /  3.  1.  0
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  
  
  ff1err: Input #0, rtsp, from 'rtsp://admin:password@192.168.1.54:554/axis-media/media.amp?videocodec=h264&resolution=1280x720':
  
    Metadata:
  
      title           : Session streamed with GStreamer
  
      comment         : rtsp-server
  
    Duration: N/A, start: 0.033344
  
  ff1err: , bitrate: N/A
  
      Stream #0:0: Video: h264 (Main), yuvj420p(pc, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], 30 fps, 30 tbr, 90k tbn, 180k tbc
  
  
  
  ff1err: [swscaler @ 0x7f8df281bc00] deprecated pixel format used, make sure you did set range correctly
  
  
  
  ff1err: [libvpx-vp9 @ 0x7f8df2800600] v1.6.1
  
  
  
  ff1err: Output #0, webm_chunk, to 'public/glass_360_%d.chk':
  
    Metadata:
  
      title           : Session streamed with GStreamer
  
      comment         : rtsp-server
  
      encoder         : Lavf57.56.101
  
  
  
  ff1err:     Stream #0:0: Video: vp9 (libvpx-vp9), yuv420p(pc), 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 200 kb/s, 25 fps, 1k tbn, 25 tbc
  
      Metadata:
  
        encoder         : Lavc57.64.101 libvpx-vp9
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> vp9 (libvpx-vp9))
  
  Press [q] to stop, [?] for help
  
  
  
  ff1err: frame=   10 fps=0.0 q=0.0 size=N/A time=00:00:00.36 bitrate=N/A speed=0.71x    
  
  ff1err: frame=   25 fps= 25 q=0.0 size=N/A time=00:00:00.96 bitrate=N/A speed=0.946x    
  
  ff1err: frame=   40 fps= 26 q=0.0 size=N/A time=00:00:01.56 bitrate=N/A speed=1.03x    
  
  ff1err: frame=   55 fps= 27 q=0.0 size=N/A time=00:00:02.16 bitrate=N/A speed=1.07x    
  
  ff1err: frame=   70 fps= 28 q=0.0 size=N/A time=00:00:02.76 bitrate=N/A speed=1.09x    
  
  ff1err: frame=   85 fps= 28 q=0.0 size=N/A time=00:00:03.36 bitrate=N/A speed=1.11x    
  
  ff2err: ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.1.2/include/openjpeg-2.1 --enable-nonfree --enable-vda
  
  
  
  ff2err:   libavutil      55. 34.101 / 55. 34.101
  
    libavcodec     57. 64.101 / 57. 64.101
  
    libavformat    57. 56.101 / 57. 56.101
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libavresample   3.  1.  0 /  3.  1.  0
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  
  
  ff2err: [webm_dash_manifest @ 0x7fbc5b80b400] Could not find codec parameters for stream 0 (Video: vp9, none, 1280x720): unspecified pixel format
  
  Consider increasing the value for the 'analyzeduration' and 'probesize' options
  
  
  
  ff2err: Input #0, webm_dash_manifest, from 'public/glass_360.hdr':
  
    Metadata:
  
      title           : Session streamed with GStreamer
  
      encoder         : Lavf57.56.101
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: vp9, none, 1280x720
  
  ff2err: , SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
  
      Metadata:
  
        webm_dash_manifest_file_name: glass_360.hdr
  
        webm_dash_manifest_track_number: 1
  
  
  
  ff2err: Could not write header for output file #0 (incorrect codec parameters ?): Operation not permittedStream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
  
  
  ff2err:     Last message repeated 1 times
  
  
  
  ff1err: frame=  101 fps= 29 q=0.0 size=N/A time=00:00:04.00 bitrate=N/A speed=1.13x    
  
  ff1err: frame=  116 fps= 29 q=0.0 size=N/A time=00:00:04.60 bitrate=N/A speed=1.14x    
  
  ff1err: frame=  131 fps= 29 q=0.0 size=N/A time=00:00:05.20 bitrate=N/A speed=1.15x    
  
  ff1err: frame=  146 fps= 29 q=0.0 size=N/A time=00:00:05.80 bitrate=N/A speed=1.15x    
  
  ff1err: frame=  161 fps= 29 q=0.0 size=N/A time=00:00:06.40 bitrate=N/A speed=1.15x    
  
  ff1err: frame=  177 fps= 29 q=0.0 size=N/A time=00:00:07.04 bitrate=N/A speed=1.16x    
  
  ff1err: frame=  192 fps= 29 q=0.0 size=N/A time=00:00:07.64 bitrate=N/A speed=1.16x    
  
  ff1err: frame=  207 fps= 29 q=0.0 size=N/A time=00:00:08.24 bitrate=N/A speed=1.16x    
  
  ff1err: frame=  222 fps= 29 q=0.0 size=N/A time=00:00:08.84 bitrate=N/A speed=1.17x    
  
  ff1err: frame=  237 fps= 29 q=0.0 size=N/A time=00:00:09.44 bitrate=N/A speed=1.17x    
  
  ff1err: frame=  252 fps= 29 q=0.0 size=N/A time=00:00:10.04 bitrate=N/A speed=1.17x  

  Why is ffmpeg creating an empty .mpd file ?