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• FFMPEG with hardware codec support

  28 janvier 2012, par mctma

  I have built a simple media player using ffmpeg on Android 2.2. Hardware is an arm cortex-a8 based 1GHz processor, 512 MB RAM. I am getting low performance, around 15 FPS for 800x600 mp4 video. I have a couple of questions on how I can improve the performance

  • How can I use the hardware codecs available on my target device. How can I configure ffmpeg to use the available hardware decoders ? Does the GPU or graphics driver have to expose some standard API like OpenMax IL in order to this ?

  • What are the options that should be enabled when building ffmpeg so that it can be optimized for my target hardware ? Something like :
    --cpu=cortex=a8 --extra-cflags="-mfpu=neon" ...

  I have already looked around the net but I couldn't find the answers that I am looking for. I hope someone can advice me on this.

  Thanks in advance !

• Using OpenMAX (IL ?) for audio/video decoding on Android

  14 septembre 2012, par Christopher Corsi

  Many of the newer hardware platforms running Android, in particular NVIDIA's Tegra 2, support OpenMAX for media acceleration. It's effectively impossible on today's devices to decode 720p video without this support, but the number of demuxers supported on Android are quite slim. The only public API I've been able to find has been through the MediaPlayer class in the Android SDK. There are multiple places in the Android source tree with OpenMAX related tidbits, however.

  On my device (Samsung Galaxy Tab 10.1) I've got access to hardware decoders through a multitude of OpenMAX libs in /system/lib, and it would be great to interface my video application with these. Can anyone point me to information on implementing a decoder powered by OpenMAX ? I've found the documentation from Khronos, but nothing in the way of example code or tutorials. I've already got demuxing and even software decoding taken care of (via libavcodec/libavformat), I'd just like to put hooks in to enable hardware encoding. I'm also assuming here it would be necessary to link directly to the ones available on the device, which makes it pretty lackluster in terms of portability, but it works.

  Alternatively, I'm interested in anything anyone knows about private APIs for accessing the video decoding available on Tegra 2 devices. Especially if there's a vdpau interface like what NVIDIA implements for desktop linux distributions, since there's plenty available for that - but I wasn't able to find shared libraries that indicate that support.

• Convert wmv to mp4 with ffmpeg failing

  10 janvier 2012, par Morph

  I've seen quite a few posts on this, but I can't piece together whether I am doing things right, wrong, or need to download more stuff. I am converting from wmv to mp4 without complaints, but then when I go to play it on the browser window (HTML5) the player just turns grey and blanks out the controls.

  Installing ffmpeg I do

  ./configure --disable-yasm ; make ; make install

  Unless I include the disable yasm it wont go any further. Then I do

  ffmpeg -i myvideo.wmv myvideo.mp4

  All good so far. In my html source I have :

    <video width="320" height="240" controls="controls">
  
    <source src="myvideo.mp4" type="&#39;video/mp4;" codecs="avc1.42E01E, mp4a.40.2"></source>
  
    Your browser does not support the video tag.
  
    </video>

  I am playing this in Chrome 15 and ffmpeg -v is

  ffmpeg version 0.8.6, Copyright (c) 2000-2011 the FFmpeg developers
  
  built on Dec  1 2011 15:42:06 with gcc 4.1.2 20080704 (Red Hat 4.1.2-51)
  
  configuration: --disable-yasm
  
  libavutil    51.  9. 1 / 51.  9. 1
  
  libavcodec   53.  7. 0 / 53.  7. 0
  
  libavformat  53.  4. 0 / 53.  4. 0
  
  libavdevice  53.  1. 1 / 53.  1. 1
  
  libavfilter   2. 23. 0 /  2. 23. 0
  
  libswscale    2.  0. 0 /  2.  0. 0

  So I get the HTML5, click on it to play the movie but then the control bar greys out, leaving the play button, but then the play button cannot be clicked and nothing plays.

  Is there something wrong with what I have done above ? Do I need to download some separate mp4 driver and compile it ? I see people referring to h.264 but I thoughts ffmpeg had that already included...