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• Use opencv to encode into flv, playable by flash player

  13 février 2012, par Hemang Shah

  I've compiled ffmpeg with libx264 using configure options given at 1.

  This results in the following codecs being available in ffmpeg :

  $ ffmpeg -codecs | grep "264\|flv"
  
  ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
  
  built on Feb 10 2012 13:54:15 with gcc 4.6.1
  
  configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-nonfree --enable-postproc --enable-version3 --enable-x11grab
  
  libavutil      51. 34.101 / 51. 34.101
  
  libavcodec     53. 60.100 / 53. 60.100
  
  libavformat    53. 31.100 / 53. 31.100
  
  libavdevice    53.  4.100 / 53.  4.100
  
  libavfilter     2. 60.100 /  2. 60.100
  
  libswscale      2.  1.100 /  2.  1.100
  
  libswresample   0.  6.100 /  0.  6.100
  
  libpostproc    52.  0.100 / 52.  0.100
  
  DEVSD  flv             Flash Video (FLV) / Sorenson Spark / Sorenson H.263
  
  D V D  h264            H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  D V D  h264_vdpau      H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (VDPAU acceleration)
  
  EV    libx264         libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  EV    libx264rgb      libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 RGB

  After this, I compiled opencv. Here is partial cmake result :

  --   Video I/O:
  
  --     DC1394 1.x:                 NO
  
  --     DC1394 2.x:                 NO
  
  --     FFMPEG:                     YES
  
  --       codec:                    YES
  
  --       format:                   YES
  
  --       util:                     YES
  
  --       swscale:                  YES
  
  --       gentoo-style:             YES
  
  --     GStreamer:                  YES
  
  --     UniCap:                     NO
  
  --     PvAPI:                      NO
  
  --     V4L/V4L2:                   /1
  
  --     Xine:                       NO

  Now, using opencv's VideoWriter, I tried to encode into flv with the following FOURCC codes :
  FLV1, X264

  While the FLV1 results in a video file not playable by flash player, but playabe by vlc ; X264 produces no results at all.
  Here is the console output for X264, resulting in a 0 byte file.

  Output #0, flv, to 'd.flv' :
  Stream #0.0 : Video : [0][0][0][0] / 0x0000, yuv420p, 320x240, q=2-31, 4915 kb/s, 90k tbn, 24 tbc

  Do you see anything amiss or incorrect ?
  thanks,

• ffmpeg command for faster encoding at a decent bitrate with smaller file size

  14 septembre 2016, par Blair Holmes

  I’m currently using an implementation of ffmpeg on my android app. I’m allowing users to take short videos within my app and then when they upload them to the server, I’m crunching them down with ffmpeg to decrease file size so they’re not passing huge amounts of data over the wire.

  the problem is, it’s taking forever to encode the videos on the android device. These videos usually aren’t longer than 45 seconds and can take 20 minutes to encode. I’ve done some playing around with different switches / parameters on the ffmpeg command line and I now have it at a more comfortable time, but the file sizes are significantly bigger. I’m just not sure what codec I should use (fastest encoding but with decent quality output), how ffmpeg handles changing size (aspect ratio) in terms of speed of encoding etc.

  Here are the two commands I’ve been using. This first one outputs the file size / quality that I want, but it just takes way too long to encode, not to mention it makes my device get really hot while it’s encoding for so long :

  ffmpeg -i input.mp4 -b:v 1024k -c:a copy -vf scale=960:540 output.mp4

  I’ve tweaked the bitrate some on that as well as changed the scale to a smaller size, but I don’t want to have to make the videos really small (in terms of scale) to accomplish a faster encoding. this second command goes a lot faster but makes the file size significantly bigger :

  ffmpeg -i input.mp4 -vcodec libx264 -preset fast -c:a copy -s 960x540 output.mp4

  I’d like to find a happy medium (smaller file size but faster encoding) keeping the video scale size close to the original. ffmpeg just has so many different parameters / switches that it’s difficult to wrap my head around what I should be doing.

  EDIT : adding ffmpeg output.

  ffmpeg -i input.mp4 -vcodec libx264 -crf 30 -preset veryfast -c:a copy -s 960x540 output.mp4

      09-13 11:06:28.330 10881-10881/someapp D/home: ffmpeg version n3.0.1 Copyright (c) 2000-2016 the FFmpeg developers
  
  09-13 11:06:28.330 10881-10881/someapp D/home:   built with gcc 4.8 (GCC)
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   configuration: --target-os=linux --cross-prefix=/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/bin/arm-linux-androideabi- --arch=arm --cpu=cortex-a8 --enable-runtime-cpudetect --sysroot=/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/sysroot --enable-pic --enable-libx264 --enable-libass --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-fontconfig --enable-pthreads --disable-debug --disable-ffserver --enable-version3 --enable-hardcoded-tables --disable-ffplay --disable-ffprobe --enable-gpl --enable-yasm --disable-doc --disable-shared --enable-static --pkg-config=/home/vagrant/SourceCode/ffmpeg-android/ffmpeg-pkg-config --prefix=/home/vagrant/SourceCode/ffmpeg-android/build/armeabi-v7a --extra-cflags='-I/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/include -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all' --extra-ldflags='-L/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/lib -Wl,-z,relro -Wl,-z,now -pie' --extra-libs='-lpng -lexpat -lm' --extra-cxxflags=
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libavutil      55. 17.103 / 55. 17.103
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libavcodec     57. 24.102 / 57. 24.102
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libavformat    57. 25.100 / 57. 25.100
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libavdevice    57.  0.101 / 57.  0.101
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libavfilter     6. 31.100 /  6. 31.100
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libswscale      4.  0.100 /  4.  0.100
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libswresample   2.  0.101 /  2.  0.101
  
  09-13 11:06:28.331 10881-10881/someapp D/home:   libpostproc    54.  0.100 / 54.  0.100
  
  09-13 11:06:28.430 10881-10881/someapp D/home: Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/storage/emulated/0/ExpeditionSpot/Videos/20160913110411.mp4':
  
  09-13 11:06:28.430 10881-10881/someapp D/home:   Metadata:
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     major_brand     : mp42
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     minor_version   : 0
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     compatible_brands: isommp42
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     creation_time   : 2016-09-13 17:04:33
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     com.android.version: 6.0.1
  
  09-13 11:06:28.430 10881-10881/someapp D/home:   Duration: 00:00:19.41, start: 0.000000, bitrate: 20222 kb/s
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 1920x1080, 19963 kb/s, SAR 1:1 DAR 16:9, 30.03 fps, 30 tbr, 90k tbn, 180k tbc (default)
  
  09-13 11:06:28.430 10881-10881/someapp D/home:     Metadata:
  
  09-13 11:06:28.430 10881-10881/someapp D/home:       creation_time   : 2016-09-13 17:04:33
  
  09-13 11:06:28.430 10881-10881/someapp D/home:       handler_name    : VideoHandle
  
  09-13 11:06:28.431 10881-10881/someapp D/home:     Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 96 kb/s (default)
  
  09-13 11:06:28.431 10881-10881/someapp D/home:     Metadata:
  
  09-13 11:06:28.431 10881-10881/someapp D/home:       creation_time   : 2016-09-13 17:04:33
  
  09-13 11:06:28.431 10881-10881/someapp D/home:       handler_name    : SoundHandle
  
  09-13 11:06:28.448 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] using SAR=1/1
  
  09-13 11:06:28.448 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] using cpu capabilities: none!
  
  09-13 11:06:28.516 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] profile High, level 3.1
  
  09-13 11:06:28.516 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] 264 - core 148 - H.264/MPEG-4 AVC codec - Copyleft 2003-2015 - http://www.videolan.org/x264.html - options: cabac=1 ref=1 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=2 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=12 lookahead_threads=4 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=10 rc=crf mbtree=1 crf=27.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  09-13 11:06:28.532 10881-10881/someapp D/home: Output #0, mp4, to '/storage/emulated/0/ExpeditionSpot/.tmp/small-20160913110411.mp4':
  
  09-13 11:06:28.532 10881-10881/someapp D/home:   Metadata:
  
  09-13 11:06:28.532 10881-10881/someapp D/home:     major_brand     : mp42
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     minor_version   : 0
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     compatible_brands: isommp42
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     com.android.version: 6.0.1
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     encoder         : Lavf57.25.100
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 960x540 [SAR 1:1 DAR 16:9], q=-1--1, 30 fps, 15360 tbn, 30 tbc (default)
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     Metadata:
  
  09-13 11:06:28.533 10881-10881/someapp D/home:       creation_time   : 2016-09-13 17:04:33
  
  09-13 11:06:28.533 10881-10881/someapp D/home:       handler_name    : VideoHandle
  
  09-13 11:06:28.533 10881-10881/someapp D/home:       encoder         : Lavc57.24.102 libx264
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     Side data:
  
  09-13 11:06:28.533 10881-10881/someapp D/home:       unknown side data type 10 (24 bytes)
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     Stream #0:1(eng): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, 96 kb/s (default)
  
  09-13 11:06:28.533 10881-10881/someapp D/home:     Metadata:
  
  09-13 11:06:28.533 10881-10881/someapp D/home:       creation_time   : 2016-09-13 17:04:33
  
  09-13 11:06:28.533 10881-10881/someapp D/home:       handler_name    : SoundHandle
  
  09-13 11:06:28.533 10881-10881/someapp D/home: Stream mapping:
  
  09-13 11:06:28.533 10881-10881/someapp D/home:   Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  
  09-13 11:06:28.533 10881-10881/someapp D/home:   Stream #0:1 -> #0:1 (copy)
  
  09-13 11:06:28.533 10881-10881/someapp D/home: Press [q] to stop, [?] for help
  
  09-13 11:06:29.102 10881-10881/someapp D/home: frame=    7 fps=0.0 q=0.0 size=       0kB time=00:00:01.04 bitrate=   0.4kbits/s speed=2.08x    
  
  09-13 11:06:29.699 10881-10881/someapp D/home: frame=   16 fps= 15 q=0.0 size=       0kB time=00:00:01.04 bitrate=   0.4kbits/s speed=0.998x    
  
  ....
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] frame I:3     Avg QP:26.83  size: 21896
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] frame P:279   Avg QP:28.76  size:  5859
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] frame B:296   Avg QP:29.93  size:   863
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] consecutive B-frames: 18.3% 32.2% 23.9% 25.6%
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] mb I  I16..4: 16.9% 54.2% 28.9%
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] mb P  I16..4:  7.7%  9.1%  0.4%  P16..4: 27.5% 11.1%  4.0%  0.0%  0.0%    skip:40.1%
  
  09-13 11:07:12.674 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] mb B  I16..4:  0.8%  0.6%  0.0%  B16..8: 10.9%  2.4%  0.1%  direct: 1.8%  skip:83.5%  L0:35.8% L1:54.2% BI:10.0%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] 8x8 transform intra:52.0% inter:41.3%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] coded y,uvDC,uvAC intra: 28.9% 26.0% 2.1% inter: 6.4% 5.0% 0.0%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] i16 v,h,dc,p: 57% 20% 17%  6%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 33% 23% 34%  1%  2%  1%  3%  2%  2%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 36% 21% 17%  2%  7%  4%  6%  4%  4%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] i8c dc,h,v,p: 59% 16% 23%  2%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] Weighted P-Frames: Y:16.8% UV:4.7%
  
  09-13 11:07:12.675 10881-10881/someapp D/home: [libx264 @ 0xf71c4400] kb/s:812.09

• FFMPEG reconnect input if error

  15 septembre 2016, par Alkitab Suhano

  I’m finding a way to make ffmpeg reconnect if any error occurered. For my case I restream from hls to rtmp for example

  ffmpeg -reconnect 1 -reconnect_at_eof 1 -reconnect_streamed 1 -reconnect_delay_max 2000 -i "input" -c:v copy -c:a aac -ar 44100 -ab 128k -ac 2 -strict -2 -f flv rtmp://output

  FFMpeg always disconnected every 10 minutes. I searched on google and can’t find stable solution for this job.

  P.S. OS is linux (Centos 7 64bit)

  Thank you,
  Akitab