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• swresample/resample : speed up build_filter by 50%

  4 novembre 2015, par Ganesh Ajjanagadde

  swresample/resample : speed up build_filter by 50%
  This speeds up build_filter by 50%. This gain should be pretty
  
  consistent across all architectures and platforms.
  Essentially, this relies on a observation that the filters have some
  
  even/odd symmetry that may be exploited during the construction of the
  
  polyphase filter bank. In particular, phases (scaled to [0, 1]) in [0.5, 1] are
  
  easily derived from [0, 0.5] and expensive reevaluation of function
  
  points are unnecessary. This requires some rather annoying even/odd
  
  bookkeeping as can be seen from the patch.
  I vaguely recall from signal processing theory more general symmetries allowing even greater
  
  optimization of the construction. At a high level, "even functions"
  
  correspond to 2, and one can imagine variations. Nevertheless, for the sake
  
  of some generality and because of existing filters, this is all that is
  
  being exploited.
  Currently, this patch relies on phase_count being even or (trivially) 1,
  
  though this is not an inherent limitation to the approach. This
  
  assumption is safe as phase_count is 1 << phase_bits, and is hence a
  
  power of two. There is no way for user API to set it to a nontrivial odd
  
  number. This assumption has been placed as an assert in the code.
  To repeat, this assumes even symmetry of the filters, which is the most common
  
  way to get generalized linear phase anyway and is true of all currently
  
  supported filters.
  As a side note, accuracy should be identical or perhaps slightly better
  
  due to this "forcing" filter symmetries leading to a better phase
  
  characteristic. As before, I can’t test this claim easily, though it may
  
  be of interest.
  Patch tested with FATE.
  Sample benchmark (x86-64, Haswell, GNU/Linux) :
  test : swr-resample-dblp-44100-2626
  new :
  
  527376779 decicycles in build_filter(loop 1000),     256 runs,      0 skips
  
  524361765 decicycles in build_filter(loop 1000),     512 runs,      0 skips
  
  516552574 decicycles in build_filter(loop 1000),    1024 runs,      0 skips
  old :
  
  974178658 decicycles in build_filter(loop 1000),     256 runs,      0 skips
  
  972794408 decicycles in build_filter(loop 1000),     512 runs,      0 skips
  
  954350046 decicycles in build_filter(loop 1000),    1024 runs,      0 skips
  Note that lower level optimizations are entirely possible, I focussed on
  
  getting the high level semantics correct. In any case, this should
  
  provide a good foundation.
  Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Signed-off-by : Ganesh Ajjanagadde <gajjanagadde@gmail.com>
  

  • [DH] libswresample/resample.c

• How to merge list of videos with frame specifiec order using ffmpeg ?

  9 décembre 2015, par Il'ya Zhenin

  I have a list of files :

  even_0.avi
  
  odd_0.avi
  
  even_1.avi
  
  odd_1.avi
  
  ...
  
  even_n.avi
  
  odd_n.avi

  And I want to merge them in a single video file in such a way, that zero frame would be taken from even_0.avi, first frame from odd_0.avi, second - from even_0.avi and so on.

  And if all frames in even_0.avi are taken, then next frame we will take from even_1.avi, next from odd_0.avi, next again from even_1.avi. Basically, when one video ends, we just start taking frames from the next video with prefix "even_" or "odd_".

  I just started using ffmpeg, know, how to simply merge videos, change resolution, fps and so on, but this is beyond my power, so, please, help.

• FFMPEG RGB Lossless conversion video

  29 août 2017, par DCDCDC

  I have been experiencing difficulty in finding many answers with FFMPEG documentation, forums and here.
  What I am trying to do is a compress a screen capture video but with just RGB data.
  The steps I am currently taking are ;

  ffmpeg -f avfoundation -pix_fmt 0rgb -r "30" -i "1" -vcodec libx264rgb -pix_fmt rgb24 -crf 0 -t 25 -q 0 -y ~/Desktop/RGB.mkv 
  
  
  
  south-58-45:~ danielcarter$ ffmpeg -f avfoundation -pix_fmt 0rgb -r "30" -i "1" -vcodec libx264rgb -pix_fmt rgb24 -crf 0 -t 170 -q 0 -y -v info ~/Desktop/output.mkv
  
  ffmpeg version 3.3 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 8.1.0 (clang-802.0.41)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  
    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
  
  [avfoundation @ 0x7fc39d004c00] Stream #0: not enough frames to estimate rate; consider increasing probesize
  
  Input #0, avfoundation, from '1':
  
    Duration: N/A, start: 175270.249500, bitrate: N/A
  
      Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1440x900, 1000k tbr, 1000k tbn, 1000k tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264rgb))
  
  Press [q] to stop, [?] for help
  
  [libx264rgb @ 0x7fc39d13ea00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
  
  [libx264rgb @ 0x7fc39d13ea00] profile High 4:4:4 Predictive, level 4.0, 4:4:4 8-bit
  
  [libx264rgb @ 0x7fc39d13ea00] 264 - core 148 r2748 97eaef2 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=0 mixed_ref=1 me_range=16 chroma_me=1 trellis=0 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc=cqp mbtree=0 qp=0
  
  Output #0, matroska, to '/Users/danielcarter/Desktop/output.mkv':
  
    Metadata:
  
      encoder         : Lavf57.71.100
  
      Stream #0:0: Video: h264 (libx264rgb) (H264 / 0x34363248), rgb24, 1440x900, q=-1--1, 30 fps, 1k tbn, 30 tbc
  
      Metadata:
  
        encoder         : Lavc57.89.100 libx264rgb
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
  
  frame= 5100 fps= 30 q=-1.0 Lsize=   12167kB time=00:02:49.96 bitrate= 586.4kbits/s speed=0.999x    
  
  video:12134kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.267659%
  
  [libx264rgb @ 0x7fc39d13ea00] frame I:21    Avg QP: 0.00  size:430796
  
  [libx264rgb @ 0x7fc39d13ea00] frame P:5079  Avg QP: 0.00  size:   665
  
  [libx264rgb @ 0x7fc39d13ea00] mb I  I16..4: 61.3%  0.0% 38.7%
  
  [libx264rgb @ 0x7fc39d13ea00] mb P  I16..4:  0.1%  0.0%  0.0%  P16..4:  0.0%  0.0%  0.0%  0.0%  0.0%    skip:99.9%
  
  [libx264rgb @ 0x7fc39d13ea00] 8x8 transform intra:0.0% inter:11.2%
  
  [libx264rgb @ 0x7fc39d13ea00] coded y,u,v intra: 48.0% 31.6% 29.0% inter: 0.0% 0.0% 0.0%
  
  [libx264rgb @ 0x7fc39d13ea00] i16 v,h,dc,p: 76% 22%  2%  0%
  
  [libx264rgb @ 0x7fc39d13ea00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 46% 35%  7%  2%  2%  1%  1%  1%  3%
  
  [libx264rgb @ 0x7fc39d13ea00] Weighted P-Frames: Y:0.0% UV:0.0%
  
  [libx264rgb @ 0x7fc39d13ea00] ref P L0: 83.1%  6.4%  5.3%  5.2%
  
  [libx264rgb @ 0x7fc39d13ea00] kb/s:584.71

  This captures the screen on my mac. To the best of my knowledge, this creates a lossless file and I have compared screen shots that confirm this.
  The next step is where I think I have an issue.
  Because I want to run the compression on raw RGB data I need to convert the MKV to an RGB file ;

  ffmpeg -i ~/Desktop/RGB.mkv -c:v rawvideo -pix_fmt rgb24 -crf 0 -ss 00:00:03 -to 00:02:01 -q 0 -y ~/Desktop/out.rgb
  
  
  
  south-58-45:~ danielcarter$ ffmpeg -i ~/Desktop/output.mkv -c:v rawvideo -pix_fmt rgb24 -crf 0 -ss 00:00:03 -to 00:02:01 -q 0 -y ~/Desktop/out.rgb
  
  ffmpeg version 3.3 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 8.1.0 (clang-802.0.41)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  
    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 '/Users/danielcarter/Desktop/output.mkv':
  
    Metadata:
  
      ENCODER         : Lavf57.71.100
  
    Duration: 00:02:50.00, start: 0.000000, bitrate: 586 kb/s
  
      Stream #0:0: Video: h264 (High 4:4:4 Predictive), gbrp(tv, gbr/unknown/unknown, progressive), 1440x900, 30 fps, 30 tbr, 1k tbn, 60 tbc (default)
  
      Metadata:
  
        ENCODER         : Lavc57.89.100 libx264rgb
  
        DURATION        : 00:02:50.000000000
  
  Codec AVOption crf (Select the quality for constant quality mode) specified for output file #0 (/Users/danielcarter/Desktop/out.rgb) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> rawvideo (native))
  
  Press [q] to stop, [?] for help
  
  Output #0, rawvideo, to '/Users/danielcarter/Desktop/out.rgb':
  
    Metadata:
  
      encoder         : Lavf57.71.100
  
      Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 1440x900, q=2-31, 933120 kb/s, 30 fps, 30 tbn, 30 tbc (default)
  
      Metadata:
  
        DURATION        : 00:02:50.000000000
  
        encoder         : Lavc57.89.100 rawvideo
  
  frame= 3540 fps=111 q=-0.0 Lsize=13440938kB time=00:01:58.00 bitrate=933120.0kbits/s speed=3.68x    
  
  video:13440938kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%

  Once I have this I can then compress and decompress successfully. I then get a working file to play back using ;

  ffmpeg -f rawvideo -vcodec rawvideo -s 1440x900 -r 30 -pix_fmt rgb24 -i ~/Desktop/out.rgb -c:v libx264rgb -pix_fmt rgb24 -x264opts keyint=300:min-keyint=300:no-scenecut -y -crf 0 ~/Desktop/rgbplay.mkv
  
  
  
  south-58-45:~ danielcarter$ ffmpeg -f rawvideo -vcodec rawvideo -s 1440x900 -r 30 -pix_fmt rgb24 -i ~/Desktop/out.rgb -c:v libx264rgb -pix_fmt rgb24 -x264opts keyint=300:min-keyint=300:no-scenecut -y -crf 0 ~/Desktop/rgbplay.mkv
  
  ffmpeg version 3.3 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 8.1.0 (clang-802.0.41)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  
    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
  
  [rawvideo @ 0x7fb1f9002600] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, rawvideo, from '/Users/danielcarter/Desktop/out.rgb':
  
    Duration: 00:01:58.00, start: 0.000000, bitrate: 933120 kb/s
  
      Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 1440x900, 933120 kb/s, 30 tbr, 30 tbn, 30 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264rgb))
  
  Press [q] to stop, [?] for help
  
  [libx264rgb @ 0x7fb1f9010c00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
  
  [libx264rgb @ 0x7fb1f9010c00] profile High 4:4:4 Predictive, level 4.0, 4:4:4 8-bit
  
  [libx264rgb @ 0x7fb1f9010c00] 264 - core 148 r2748 97eaef2 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=0 mixed_ref=1 me_range=16 chroma_me=1 trellis=0 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=2 keyint=300 keyint_min=151 scenecut=0 intra_refresh=0 rc=cqp mbtree=0 qp=0
  
  Output #0, matroska, to '/Users/danielcarter/Desktop/rgbplay.mkv':
  
    Metadata:
  
      encoder         : Lavf57.71.100
  
      Stream #0:0: Video: h264 (libx264rgb) (H264 / 0x34363248), rgb24, 1440x900, q=-1--1, 30 fps, 1k tbn, 30 tbc
  
      Metadata:
  
        encoder         : Lavc57.89.100 libx264rgb
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
  
  frame= 3540 fps= 64 q=-1.0 Lsize=    8319kB time=00:01:57.96 bitrate= 577.7kbits/s speed=2.13x    
  
  video:8297kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.273154%
  
  [libx264rgb @ 0x7fb1f9010c00] frame I:12    Avg QP: 0.00  size:437670
  
  [libx264rgb @ 0x7fb1f9010c00] frame P:3528  Avg QP: 0.00  size:   919
  
  [libx264rgb @ 0x7fb1f9010c00] mb I  I16..4: 61.9%  0.0% 38.1%
  
  [libx264rgb @ 0x7fb1f9010c00] mb P  I16..4:  0.1%  0.0%  0.0%  P16..4:  0.0%  0.0%  0.0%  0.0%  0.0%    skip:99.8%
  
  [libx264rgb @ 0x7fb1f9010c00] 8x8 transform intra:0.0% inter:15.1%
  
  [libx264rgb @ 0x7fb1f9010c00] coded y,u,v intra: 49.7% 36.5% 33.7% inter: 0.0% 0.0% 0.0%
  
  [libx264rgb @ 0x7fb1f9010c00] i16 v,h,dc,p: 73% 25%  1%  0%
  
  [libx264rgb @ 0x7fb1f9010c00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 45% 36%  7%  2%  2%  2%  2%  1%  3%
  
  [libx264rgb @ 0x7fb1f9010c00] Weighted P-Frames: Y:0.0% UV:0.0%
  
  [libx264rgb @ 0x7fb1f9010c00] ref P L0: 81.3%  7.7%  6.7%  4.3%
  
  [libx264rgb @ 0x7fb1f9010c00] kb/s:575.96

  But here I have pixel variance. My guess is there is a RGB-YUV-RGB conversion happening somewhere but I am not smart enough to work out where.
  If any of you can help I would forever grateful.

  Here is a picture of the two stills side by side that shows the differences ;

  pixel difference

  If you need anything more I can post it also.
  Cheers,
  DC