Recherche avancée

Sur d’autres sites (5490)

• opus : add a native Opus encoder

  11 février 2017, par Rostislav Pehlivanov

  opus : add a native Opus encoder
  This marks the first time anyone has written an Opus encoder without
  
  using any libopus code. The aim of the encoder is to prove how far
  
  the format can go by writing the craziest encoder for it.
  Right now the encoder’s basic, it only supports CBR encoding, however
  
  internally every single feature the CELT layer has is implemented
  
  (except the pitch pre-filter which needs to work well with the rest of
  
  whatever gets implemented). Psychoacoustic and rate control systems are
  
  under development.
  The encoder takes in frames of 120 samples and depending on the value of
  
  opus_delay the plan is to use the extra buffered frames as lookahead.
  
  Right now the encoder will pick the nearest largest legal frame size and
  
  won’t use the lookahead, but that’ll change once there’s a
  
  psychoacoustic system.
  Even though its a pretty basic encoder its already outperforming
  
  any other native encoder FFmpeg has by a huge amount.
  The PVQ search algorithm is faster and more accurate than libopus’s
  
  algorithm so the encoder’s performance is close to that of libopus
  
  at zero complexity (libopus has more SIMD).
  
  The algorithm might be ported to libopus or other codecs using PVQ in
  
  the future.
  The encoder still has a few minor bugs, like desyncs at ultra low
  
  bitrates (below 9kbps with 20ms frames).
  Signed-off-by : Rostislav Pehlivanov <atomnuker@gmail.com>
  

  • [DH] configure
  • [DH] libavcodec/Makefile
  • [DH] libavcodec/allcodecs.c
  • [DH] libavcodec/opus_celt.h
  • [DH] libavcodec/opus_pvq.c
  • [DH] libavcodec/opus_pvq.h
  • [DH] libavcodec/opusenc.c

• Split video with ffmpeg segment option is missing frame

  9 février 2024, par Dan

  I’m trying to get the ffmpeg “segment” option to split my video into segments at the Iframes. I'm using ffmpeg V6.1.1.

  


  First I added time stamps to each frame of my video so that when it plays, I can see exactly which frame is being displayed. I used this command :

  


  ffmpeg -i In.mp4 -vf "drawtext=fontfile='C :\Windows\Fonts\Arial.ttf' : text='%frame_num :~ %pts':fontsize=200 : r=25 : x=(w-tw)/2 : y=h-(2*lh) : fontcolor=white : box=1 : boxcolor=0x00000099" -y Out.mp4

  


  Then I used ffprobe to confirm that the video is 30 FPS and the Iframes are as follows :

  


  0.000000
4.933333
10.000000
11.533333
18.866667
24.966667

  


  Based on these Iframe times, I’d expect the following segments :

  


  





  


  


  


  


  


  


  



  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  


  Start Frame	Start Time	End Frame	End Time
  0	0	147	4.900000
  148	4.933333	299	9.966667
  300	10.000000	345	11.500000
  346	11.533333	565	18.833334
  566	18.866667	748	24.933334
  749	24.966667	867	28.906667

  


  


  When I use ffmpeg to split the video into segments with the following command, I get six files as expected :

  


  ffmpeg -i Out.mp4 -f segment -c copy -reset_timestamps 1 -map 0 "Out %d.mp4"

  


  When I play the segments, they are all correct except the first segment file (Out 0.mp4). It seems to be missing the last frame. It contains frames 0 to 146 (4.866667 sec) but should also include frame 147 (4.9 sec). All the other segment files are as expected.

  


  I’ve tried this on several different mp4 videos and they all are missing the last frame on the first segments.

  


  Any idea why my first segment files is missing the last frame of the segment ?

  


  Could this be an ffmpeg bug ?

  


  Thanks for the help !
Dan

  


  Here is my console session with all output :

  


  C:\> ffprobe Out.mp4
ffprobe version 2023-12-21-git-1e42a48e37-full_build-www.gyan.dev Copyright (c) 2007-2023 the FFmpeg developers
  built with gcc 12.2.0 (Rev10, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --pkg-config=pkgconf --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-dxva2 --enable-d3d11va --enable-libvpl --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2 --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      58. 36.100 / 58. 36.100
  libavcodec     60. 36.100 / 60. 36.100
  libavformat    60. 20.100 / 60. 20.100
  libavdevice    60.  4.100 / 60.  4.100
  libavfilter     9. 14.100 /  9. 14.100
  libswscale      7.  6.100 /  7.  6.100
  libswresample   4. 13.100 /  4. 13.100
  libpostproc    57.  4.100 / 57.  4.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Out.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : Short 4k video sample - 4K Ultra HD (3840x2160)
    date            : 2014:05:24 19:00:00
    encoder         : Lavf60.20.100
  Duration: 00:00:28.96, start: 0.000000, bitrate: 3181 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 3045 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
      Metadata:
        handler_name    : VideoHandler
        vendor_id       : [0][0][0][0]
        encoder         : Lavc60.36.100 libx264
  Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
      Metadata:
        handler_name    : SoundHandler
        vendor_id       : [0][0][0][0]

C:\ ffprobe -loglevel error -skip_frame nokey -select_streams v:0 -show_entries frame=pts_time -of csv=print_section=0 Out.mp4
0.000000,
4.933333
10.000000
11.533333
18.866667
24.966667

C:\ ffmpeg -i Out.mp4 -f segment -c copy -reset_timestamps 1 -map 0 "Out %1d.mp4"
ffmpeg version 2023-12-21-git-1e42a48e37-full_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 12.2.0 (Rev10, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --pkg-config=pkgconf --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-dxva2 --enable-d3d11va --enable-libvpl --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2 --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      58. 36.100 / 58. 36.100
  libavcodec     60. 36.100 / 60. 36.100
  libavformat    60. 20.100 / 60. 20.100
  libavdevice    60.  4.100 / 60.  4.100
  libavfilter     9. 14.100 /  9. 14.100
  libswscale      7.  6.100 /  7.  6.100
  libswresample   4. 13.100 /  4. 13.100
  libpostproc    57.  4.100 / 57.  4.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Out.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : Short 4k video sample - 4K Ultra HD (3840x2160)
    date            : 2014:05:24 19:00:00
    encoder         : Lavf60.20.100
  Duration: 00:00:28.96, start: 0.000000, bitrate: 3181 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 3045 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
      Metadata:
        handler_name    : VideoHandler
        vendor_id       : [0][0][0][0]
        encoder         : Lavc60.36.100 libx264
  Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
      Metadata:
        handler_name    : SoundHandler
        vendor_id       : [0][0][0][0]
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
[segment @ 00000195bbc52940] Opening 'Out 0.mp4' for writing
Output #0, segment, to 'Out %1d.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : Short 4k video sample - 4K Ultra HD (3840x2160)
    date            : 2014:05:24 19:00:00
    encoder         : Lavf60.20.100
  Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 3045 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
      Metadata:
        handler_name    : VideoHandler
        vendor_id       : [0][0][0][0]
        encoder         : Lavc60.36.100 libx264
  Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
      Metadata:
        handler_name    : SoundHandler
        vendor_id       : [0][0][0][0]
Press [q] to stop, [?] for help
[segment @ 00000195bbc52940] Opening 'Out 1.mp4' for writing
[segment @ 00000195bbc52940] Opening 'Out 2.mp4' for writing
[segment @ 00000195bbc52940] Opening 'Out 3.mp4' for writing
[segment @ 00000195bbc52940] Opening 'Out 4.mp4' for writing
[segment @ 00000195bbc52940] Opening 'Out 5.mp4' for writing
[out#0/segment @ 00000195bc3e8cc0] video:10757kB audio:456kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
size=N/A time=00:00:28.86 bitrate=N/A speed= 322x


  


• swresample/resample : fix return value of build_filter

  18 octobre 2016, par Muhammad Faiz

  swresample/resample : fix return value of build_filter
  return AVERROR code on error
  Signed-off-by : Muhammad Faiz <mfcc64@gmail.com>
  

  • [DH] libswresample/resample.c