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• Decoding VP8 On A Sega Dreamcast

  20 février 2011, par Multimedia Mike — Sega Dreamcast, VP8

  I got Google’s libvpx VP8 codec library to compile and run on the Sega Dreamcast with its Hitachi/Renesas SH-4 200 MHz CPU. So give Google/On2 their due credit for writing portable software. I’m not sure how best to illustrate this so please accept this still photo depicting my testbench Dreamcast console driving video to my monitor :

  
  
  

  Why ? Because I wanted to try my hand at porting some existing software to this console and because I tend to be most comfortable working with assorted multimedia software components. This seemed like it would be a good exercise.

  You may have observed that the video is blue. Shortest, simplest answer : Pure laziness. Short, technical answer : Path of least resistance for getting through this exercise. Longer answer follows.

  Update : I did eventually realize that the Dreamcast can work with YUV textures. Read more in my followup post.

  Process and Pitfalls
  libvpx comes with a number of little utilities including decode_to_md5.c. The first order of business was porting over enough source files to make the VP8 decoder compile along with the MD5 testbench utility.

  Again, I used the KallistiOS (KOS) console RTOS (aside : I’m still working to get modern Linux kernels compiled for the Dreamcast). I started by configuring and compiling libvpx on a regular desktop Linux system. From there, I was able to modify a number of configuration options to make the build more amenable to the embedded RTOS.
  
  I had to create a few shim header files that mapped various functions related to threading and synchronization to their KOS equivalents. For example, KOS has a threading library cleverly named kthreads which is mostly compatible with the more common pthread library functions. KOS apparently also predates stdint.h, so I had to contrive a file with those basic types.

  So I got everything compiled and then uploaded the binary along with a small VP8 IVF test vector. Imagine my surprise when an MD5 sum came out of the serial console. Further, visualize my utter speechlessness when I noticed that the MD5 sum matched what my desktop platform produced. It worked !

  Almost. When I tried to decode all frames in a test vector, the program would invariably crash. The problem was that the file that manages motion compensation (reconinter.c) needs to define MUST_BE_ALIGNED which compiles byte-wise block copy functions. This is necessary for CPUs like the SH-4 which can’t load unaligned data. Apparently, even ARM CPUs these days can handle unaligned memory accesses which is why this isn’t a configure-time option.

  Showing The Work
  I completed the first testbench application which ran the MD5 test on all 17 official IVF test vectors. The SH-4/Dreamcast version aces the whole suite.

  However, this is a video game console, so I had better be able to show the decoded video. The Dreamcast is strictly RGB— forget about displaying YUV data directly. I could take the performance hit to convert YUV -> RGB. Or, I could just display the intensity information (Y plane) rendered on a random color scale (I chose blue) on an RGB565 texture (the DC’s graphics hardware can also do paletted textures but those need to be rearranged/twiddled/swizzled).

  Results
  So, can the Dreamcast decode VP8 video in realtime ? Sure ! Well, I really need to qualify. In the test depicted in the picture, it seems to be realtime (though I wasn’t enforcing proper frame timings, just decoding and displaying as quickly as possible). Obviously, I wasn’t bothering to properly convert YUV -> RGB. Plus, that Big Buck Bunny test vector clip is only 176x144. Obviously, no audio decoding either.

  So, realtime playback, with a little fine print.

  On the plus side, it’s trivial to get the Dreamcast video hardware to upscale that little blue image to fullscreen.

  I was able to tally the total milliseconds’ worth of wall clock time required to decode the 17 VP8 test vectors. As you can probably work out from this list, when I try to play a 320x240 video, things start to break down.

  1. Processed 29 176x144 frames in 987 milliseconds.
  2. Processed 49 176x144 frames in 1809 milliseconds.
  3. Processed 49 176x144 frames in 704 milliseconds.
  4. Processed 29 176x144 frames in 255 milliseconds.
  5. Processed 49 176x144 frames in 339 milliseconds.
  6. Processed 48 175x143 frames in 2446 milliseconds.
  7. Processed 29 176x144 frames in 432 milliseconds.
  8. Processed 2 1432x888 frames in 2060 milliseconds.
  9. Processed 49 176x144 frames in 1884 milliseconds.
  10. Processed 57 320x240 frames in 5792 milliseconds.
  11. Processed 29 176x144 frames in 989 milliseconds.
  12. Processed 29 176x144 frames in 740 milliseconds.
  13. Processed 29 176x144 frames in 839 milliseconds.
  14. Processed 49 175x143 frames in 2849 milliseconds.
  15. Processed 260 320x240 frames in 29719 milliseconds.
  16. Processed 29 176x144 frames in 962 milliseconds.
  17. Processed 29 176x144 frames in 933 milliseconds.

• "ffmpeg has text relocations" error in Android

  5 janvier 2015, par djzmo

  I’m building an Android video-sending application. I need the video to be compressed before being uploaded. In this case, I chose to use this Android wrapper of FFmpeg : https://github.com/hiteshsondhi88/ffmpeg-android-java

  FFmpeg error: WARNING: linker: /data/data/com.mycompany.myapplication/files/ffmpeg has text relocations. This is wasting memory and prevents security hardening. Please fix.
  
      ffmpeg version n2.4.2 Copyright (c) 2000-2014 the FFmpeg developers
  
      built on Oct  7 2014 15:08:46 with gcc 4.8 (GCC)
  
      configuration: --target-os=linux --cross-prefix=/home/sb/Source-Code/ffmpeg-android/toolchain-android/bin/arm-linux-androideabi- --arch=arm --cpu=cortex-a8 --enable-runtime-cpudetect --sysroot=/home/sb/Source-Code/ffmpeg-android/toolchain-android/sysroot --enable-pic --enable-libx264 --enable-libass --enable-libfreetype --enable-libfribidi --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/sb/Source-Code/ffmpeg-android/ffmpeg-pkg-config --prefix=/home/sb/Source-Code/ffmpeg-android/build/armeabi-v7a-neon --extra-cflags='-I/home/sb/Source-Code/ffmpeg-android/toolchain-android/include -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all -mfpu=neon' --extra-ldflags='-L/home/sb/Source-Code/ffmpeg-android/toolchain-android/lib -Wl,-z,relro -Wl,-z,now -pie' --extra-libs='-lpng -lexpat -lm' --extra-cxxflags=
  
      libavutil      54.  7.100 / 54.  7.100
  
      libavcodec     56.  1.100 / 56.  1.100
  
      libavformat    56.  4.101 / 56.  4.101
  
      libavdevice    56.  0.100 / 56.  0.100
  
      libavfilter     5.  1.100 /  5.  1.100
  
      libswscale      3.  0.100 /  3.  0.100
  
      libswresample   1.  1.100 /  1.  1.100
  
      libpostproc    53.  0.100 / 53.  0.100
  
      Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/storage/emulated/0/DCIM/Camera/VID_20150104_235926.mp4':
  
      Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: isommp42
  
      creation_time   : 2015-01-04 16:00:40
  
      Duration: 00:01:12.60, start: 0.000000, bitrate: 19590 kb/s
  
      Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 19364 kb/s, SAR 65536:65536 DAR 16:9, 26.73 fps, 26.92 tbr, 90k tbn, 180k tbc (default)
  
      Metadata:
  
      creation_time   : 2015-01-04 16:00:40
  
      handler_name    : VideoHandle
  
      Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 196 kb/s (default)
  
      Metadata:
  
      creation_time   : 2015-01-04 16:00:40
  
      handler_name    : SoundHandle
  
      [libx264 @ 0x40208800] using SAR=1/1
  
      [libx264 @ 0x40208800] frame MB size (120x68) > level limit (1620)
  
      [libx264 @ 0x40208800] DPB size (1 frames, 8160 mbs) > level limit (0 frames, 8100 mbs)
  
      [libx264 @ 0x40208800] MB rate (219640) > level limit (40500)
  
      [libx264 @ 0x40208800] using cpu capabilities: none!
  
      [libx264 @ 0x40208800] profile Constrained Baseline, level 3.0
  
      [libx264 @ 0x40208800] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 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=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc_lookahead=0 rc=crf mbtree=0 crf=28.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=2500 vbv_bufsize=1835 crf_max=0.0 nal_hrd=none filler=0 ip_ratio=1.40 aq=0
  
      Output #0, mp4, to '/storage/emulated/0/Android/data/com.mycompany.myapplication/cache/VID_20150104_235926.mp4':
  
      Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: isommp42
  
      encoder         : Lavf56.4.101
  
      Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1920x1080 [SAR 65536:65536 DAR 16:9], q=-1--1, 2500 kb/s, 26.92 fps, 10336 tbn, 26.92 tbc (default)
  
      Metadata:
  
      creation_time   : 2015-01-04 16:00:40
  
      handler_name    : VideoHandle
  
      encoder         : Lavc56.1.100 libx264
  
      Stream #0:1(eng): Audio: aac ([64][0][0][0] / 0x0040), 4

  Everything seemed fine when I compress small files (below 20 seconds), but when I tried to compress larger files, I seldom get the above error in the middle of the compression process, and the process was also terminated immediately. I need the application to be able to compress one minute video to about 20-35 MB.

  Here is the FFmpeg command I used :

  ffmpeg -y -i -codec:v libx264 -profile:v baseline -level 3.0 -b:v 2500k -minrate 2500k -maxrate 2500k -bufsize 1835k -pix_fmt yuv420p -preset ultrafast -crf 28 -codec:a copy

  Any idea on what went wrong ?
  Any kind of help would be very appreciated.

• FFMPEG sound not playing in video converted from audio in browsers (chrome/firefox) except safari

  7 février 2019, par Bhavik Rathod

  Sound not playing in Video (mp4) converted from Audio (mp3), Below is my code

  I am using FFMPEG version 4.1

  ffmpeg -y -loop 1 -i background.jpg -i dia.mp3 -c:v libx264 -tune stillimage -pix_fmt yuv420p -c:a ac3_fixed -b:a 128k -shortest -vf "[in]drawtext=text=Hi:x=(w-text_w)/2:y=(h-text_h):fontfile=arial.ttf:fontsize=100:fontcolor=ffffff:alpha='if(lt(t,9.2763066666667),0,if(lt(t,9.2763066666667+1),(t-9.2763066666667)/1,if(lt(t,12.83428),1,if(lt(t,12.83428+1),(1-(t-12.83428))/1,0))))'" output.mp4 2>&1

  I have tried putting -movflags +faststart as an output option

  I am using ac3_fixed because i found that fix for handle memory management, My server is getting hang on using aac no video created nothing i have to restart instance to get back to work. by using ac3_fixed everything is perfect but issue is only sound playing in chrome and firefox.

  Below is full log while using aac

  `ffmpeg version 4.1-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2018 the FFmpeg developers
  
    built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
  
    configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg
  
    libavutil      56. 22.100 / 56. 22.100
  
    libavcodec     58. 35.100 / 58. 35.100
  
    libavformat    58. 20.100 / 58. 20.100
  
    libavdevice    58.  5.100 / 58.  5.100
  
    libavfilter     7. 40.101 /  7. 40.101
  
    libswscale      5.  3.100 /  5.  3.100
  
    libswresample   3.  3.100 /  3.  3.100
  
    libpostproc    55.  3.100 / 55.  3.100
  
  Input #0, image2, from '/var/www/html/xxxxx/assets/media/guest/e0ce3bfdab4b305d00459328afb94ca6.jpg':
  
    Duration: 00:00:00.04, start: 0.000000, bitrate: 196382 kb/s
  
      Stream #0:0: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 25 tbn, 25 tbc
  
  [mp3 @ 0x5970440] Estimating duration from bitrate, this may be inaccurate
  
  Input #1, mp3, from '/var/www/html/xxxxx/assets/media/guest/e0ce3bfdab4b305d00459328afb94ca6.mp3':
  
    Metadata:
  
      title           : In the Cafe
  
      album           : British Council
  
      genre           : Blues
  
    Duration: 00:01:02.77, start: 0.000000, bitrate: 128 kb/s
  
      Stream #1:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
  
    Stream #1:0 -> #0:1 (mp3 (mp3float) -> aac (native))
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x5b91ec0] deprecated pixel format used, make sure you did set range correctly
  
  [libx264 @ 0x598e640] using SAR=1/1
  
  [libx264 @ 0x598e640] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
  
  [libx264 @ 0x598e640] profile High, level 4.0, 4:2:0, 8-bit
  
  [libx264 @ 0x598e640] 264 - core 157 r2935 545de2f - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:-3:-3 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=2.00:0.70 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-4 threads=1 lookahead_threads=1 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=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.20
  
  Output #0, mp4, to '/var/www/html/xxxxx/assets/media/guest/created_video/e0ce3bfdab4b305d00459328afb94ca6.mp4':
  
    Metadata:
  
      encoder         : Lavf58.20.100
  
      Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 25 fps, 12800 tbn, 25 tbc
  
      Metadata:
  
        encoder         : Lavc58.35.100 libx264
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
  
      Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc58.35.100 aac
  
  frame=   14 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   frame=   28 fps= 27 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   frame=   42 fps= 27 q=28.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=  frame=   44 fps= 21 q=28.0 size=     256kB time=00:00:00.02 bitrate=72266.5kbitsframe=   49 fps= 19 q=28.0 size=     256kB time=00:00:00.20 bitrate=10323.8kbitsframe=   55 fps= 18 q=28.0 size=     256kB time=00:00:00.48 bitrate=4353.4kbits/frame=   62 fps= 17 q=28.0 size=     256kB time=00:00:00.72 bitrate=2890.7kbits/frame=   68 fps= 16 q=28.0 size=     256kB time=00:00:01.00 bitrate=2088.6kbits/    
  
  `