Recherche avancée

Sur d’autres sites (7868)

• correctly escaping text in drawtext filter

  6 novembre 2013, par mente

  According to documentation %{}:, should be escaped with slash. But when I escape % the text is not added. There's error message saying Stray % near ')'. But what does it mean and how I can fix it ? Command and output :

  $ /usr/bin/ffmpeg -y -i /home/www/255871.mov -af 'aresample=async=1:min_hard_comp=0.100000' -vf 'scale=480:trunc(ow/a/2)*2,transpose=1 [in];movie=watermarks/text-box440.mov,scale=320:55 [bg];[in][bg] overlay=x=20:y=main_h-80,drawtext=fontsize=20:fix_bounds=1:fontfile=Helvetica\\:Style=bold:fontcolor=0xe6b300:text=small kitten \%\):x=30:y=h-80+ascent/2:draw=gte(t\,0)\;lt(t\,5) [out]' -pix_fmt yuv420p -r 24.39 -map_metadata -1 -movflags +faststart -f mp4 -vcodec libx264 -b:v 800k -maxrate 1100k -bufsize 2M -bt 256k -profile:vbaseline -acodec libfdk_aac -ab 64k -ar 44100 -ac 1 /tmp/kitten.mp4
  
  ffmpeg version 1.2 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Mar 15 2013 18:40:14 with gcc 4.4.6 (GCC) 20120305 (Red Hat 4.4.6-4)
  
    configuration: --enable-gpl --enable-libmp3lame --enable-libvo-aacenc --enable-libx264 --enable-version3 --enable-pthreads --enable-libfaac --enable-nonfree --enable-libfdk_a
  
  ac --enable-fontconfig --enable-libfreetype
  
    libavutil      52. 18.100 / 52. 18.100
  
    libavcodec     54. 92.100 / 54. 92.100
  
    libavformat    54. 63.104 / 54. 63.104
  
    libavdevice    54.  3.103 / 54.  3.103
  
    libavfilter     3. 42.103 /  3. 42.103
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  2.100 / 52.  2.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/www/255871.mov':
  
    Metadata:
  
      major_brand     : qt
  
      minor_version   : 0
  
      compatible_brands: qt
  
      creation_time   : 2012-07-17 07:42:35
  
      model           : iPhone 3GS
  
      model-rus       : iPhone 3GS
  
      encoder         : 4.2.1
  
      encoder-rus     : 4.2.1
  
      date            : 2012-07-17T10:42:35+0300
  
      date-rus        : 2012-07-17T10:42:35+0300
  
      make            : Apple
  
      make-rus        : Apple
  
    Duration: 00:00:09.38, start: 0.000000, bitrate: 790 kb/s
  
      Stream #0:0(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 480x360, 720 kb/s, 29.97 fps, 29.97 tbr, 600 tbn, 1200 tbc
  
      Metadata:
  
        rotate          : 90
  
        creation_time   : 2012-07-17 07:42:35
  
        handler_name    : Core Media Data Handler
  
      Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 63 kb/s
  
      Metadata:
  
        creation_time   : 2012-07-17 07:42:35
  
        handler_name    : Core Media Data Handler
  
  [Parsed_drawtext_5 @ 0x2ae9b00] Using "/usr/share/fonts/default/Type1/n019003l.pfb"
  
  [libx264 @ 0x2ae7d40] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x2ae7d40] profile Constrained Baseline, level 2.1
  
  [libx264 @ 0x2ae7d40] 264 - core 130 r2274 c832fe9 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=0 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=800 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=1100 vbv_bufsize=2000 nal_hrd=none ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to '/tmp/kitten.mp4':
  
    Metadata:
  
      encoder         : Lavf54.63.104
  
      Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 360x480, q=-1--1, 800 kb/s, 19512 tbn, 24.39 tbc
  
      Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, mono, s16, 64 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 -> libx264)
  
    Stream #0:1 -> #0:1 (aac -> libfdk_aac)
  
  Press [q] to stop, [?] for help
  
  [Parsed_drawtext_5 @ 0x2ae9b00] Stray % near ')'
  
      Last message repeated 201 times
  
  Stray % near ')'0.0 q=27.0 size=     480kB time=00:00:07.96 bitrate= 493.4kbits/s dup=0 drop=35
  
  [Parsed_drawtext_5 @ 0x2ae9b00] Stray % near ')'
  
      Last message repeated 77 times
  
  Starting second pass: moving header on top of the file
  
  frame=  231 fps=0.0 q=-1.0 Lsize=    1002kB time=00:00:09.47 bitrate= 866.6kbits/s dup=0 drop=50
  
  video:921kB audio:74kB subtitle:0 global headers:0kB muxing overhead 0.680957%
  
  [libx264 @ 0x2ae7d40] frame I:1     Avg QP:24.43  size: 13264
  
  [libx264 @ 0x2ae7d40] frame P:230   Avg QP:23.72  size:  4041
  
  [libx264 @ 0x2ae7d40] mb I  I16..4: 24.8%  0.0% 75.2%
  
  [libx264 @ 0x2ae7d40] mb P  I16..4:  2.3%  0.0%  4.8%  P16..4: 34.4% 28.8%  9.4%  0.0%  0.0%    skip:20.3%
  
  [libx264 @ 0x2ae7d40] coded y,uvDC,uvAC intra: 62.5% 54.2% 4.4% inter: 19.6% 20.3% 0.1%
  
  [libx264 @ 0x2ae7d40] i16 v,h,dc,p: 36% 29% 19% 16%
  
  [libx264 @ 0x2ae7d40] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 19% 21% 20%  6%  8%  7%  7%  6%  6%
  
  [libx264 @ 0x2ae7d40] i8c dc,h,v,p: 65% 15% 17%  3%
  
  [libx264 @ 0x2ae7d40] ref P L0: 93.4%  4.3%  2.3%
  
  [libx264 @ 0x2ae7d40] kb/s:796.32

• FFmpeg audio formats : ipod vs mov (for ALAC)

  22 juillet 2022, par Fabien Snauwaert

  In converting to Apple Lossless (ALAC) using FFmpeg, I have two options :

  


  ffmpeg -y -i whatever.wav -b:a 256k -ar 16000 -ac 1 -f ipod -acodec:a alac whatever.ipod.m4a
# Output #0, ipod, to 'content/tests/comparing-codecs/whatever.ipod.m4a':

ffmpeg -y -i whatever.wav -b:a 256k -ar 16000 -ac 1 -f mov -acodec:a alac whatever.mov.m4a
# Output #0, mov, to 'content/tests/comparing-codecs/whatever.mov.m4a':


  


  (I could also leave the -f alone, which the defaults to ipod.)

  


  This results in near identical files, from ffprobe :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'content/tests/comparing-codecs/whatever.ipod.m4a':
  Metadata:
    major_brand     : M4A
    minor_version   : 512
    compatible_brands: isomiso2
    encoder         : Lavf58.29.100
  Duration: 00:00:01.46, start: 0.000000, bitrate: 67 kb/s
    Stream #0:0(und): Audio: alac (alac / 0x63616C61), 16000 Hz, mono, s16p, 63 kb/s (default)
    Metadata:
      handler_name    : SoundHandler


  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'content/tests/comparing-codecs/whatever.mov.m4a':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf58.29.100
  Duration: 00:00:01.46, start: 0.000000, bitrate: 67 kb/s
    Stream #0:0: Audio: alac (alac / 0x63616C61), 16000 Hz, mono, s16p, 63 kb/s (default)
    Metadata:
      handler_name    : SoundHandler


  


  Only the file size is slightly different, with the ipod file 43 bytes smaller.

  


  I'm able to play both files in on macOS and iPhone, at least on the devices I had access to.

  


  My question is : is there any practical difference between formats ? Is a given format preferable for a specific use ?

  


• iOS SDK avcodec_decode_video Optimization

  6 août 2013, par Johny Cage

  I've recently started a project that relies on streaming FLV directly to an iOS device. As most famous i went with ffmpeg (and an iOS wrapper - kxmovie). To my surprise iPhone 4 is incapable of playing even SD low-bitrate FLV videos. The current implementation i'm using is decoding the video/audio/sub frames in dispatch_async while loop and copies the YUV frame data to a object, where the object is parsed to 3 textures - Y/U/V (in case of RGB color space - just parse the data) and rendered on screen. After much trial and error, i've decided to kill the whole rendering pipeline and leave only the avcodec_decode_video2 function to run. Surprisingly the FPS did not improve and videos are still unplayable.

  My question is : What can i do to improve the performance of avcodec_decode_video2 ?

  Note :
  I've tried a few commercial apps and they play the same file perfectly fine with no more than 50-60% cpu usage.

  The library is based off the 1.2 branch and this is are the build args :

  '--arch=arm',
  
  '--cpu=cortex-a8',
  
  '--enable-pic',
  
  "--extra-cflags='-arch armv7'",
  
  "--extra-ldflags='-arch armv7'",
  
  "--extra-cflags='-mfpu=neon -mfloat-abi=softfp -mvectorize-with-neon-quad'",
  
  '--enable-neon',
  
  '--enable-optimizations',
  
  '--disable-debug',
  
  '--disable-armv5te',
  
  '--disable-armv6',
  
  '--disable-armv6t2',
  
  '--enable-small',
  
  '--disable-ffmpeg',
  
  '--disable-ffplay',
  
  '--disable-ffserver',
  
  '--disable-ffprobe',
  
  '--disable-doc',
  
  '--disable-bzlib',
  
  '--target-os=darwin',
  
  '--enable-cross-compile',
  
  #'--enable-nonfree',
  
  '--enable-gpl',
  
  '--enable-version3',

  And according to Instruments the following functions take about 30% CPU usage each :

  Running Time    Self        Symbol Name
  
  37023.9ms   32.3%   13874,8                   ff_h264_decode_mb_cabac
  
  34626.2ms   30.2%   9194,7                    loop_filter
  
  29430.0ms   25.6%   173,8                     ff_h264_hl_decode_mb