3.7. Android Multimedia (Video encode/decode)¶

This application note describes video encoding using the onboard Wave5 chip found in the Texas Instruments AM62Px SoC.

Note

Currently, only decode is supported. Video encode is still done via software encoding.

The Wave5 hardware is implemented via:

the wave5 driver, located in ~/09_02_00/ti-kernel-aosp/common/drivers/media/platform/chips-media/wave5/
a firmware located in ~/09_02_00/ti-aosp-14/vendor/ti/vendor/ti/am62x/firmware/vendor/firmware/cnm/

The userspace associated component is based on the AOSP-provided v4l2_codec2 HAL. The source can be found in ~/09_02_00/ti-aosp-14/external/v4l2_codec2.

3.7.1. Testing¶

3.7.1.1. Using `atest`¶

Android provides all kind of tests to test the media framework. We can run a sample playback via atest from a development tree.

# Standard Android build commands
$ cd ${YOUR_PATH}/ti-aosp-14
$ source build/envsetup.sh
$ lunch am62p-userdebug

# install the required media files, downloads from network
$ cts/tests/tests/media/player/
$ ./copy_media.sh
$ cd -

# run the playback test
$ atest android.media.player.cts.MediaPlayerTest#testLocalVideo_MP4_H264_480x360_500kbps_25fps_AAC_Stereo_128kbps_44110Hz

3.7.1.2. Using Gallery¶

To play test videos, we can also use the Gallery app.

First, download the Big Buck Bunny test videos:

# 1080p, 60FPS, h264
$ wget http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_60fps_normal.mp4

# 4k, 30FPS, h264
$ wget http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_2160p_30fps_normal.mp4

Then, push them in the Movies folder:

$ adb push bbb_sunflower_1080p_60fps_normal.mp4 /sdcard/Movies
$ adb push bbb_sunflower_2160p_30fps_normal.mp4 /sdcard/Movies

Finally, reboot the board:

$ adb reboot

Then run the Gallery app from the UI and play the videos.

3.7.2. Debugging tips¶

3.7.2.1. List available codecs¶

dumpsys can be used to list the available codecs on an Android system. To check that the v4l2 codecs are available, run:

$ adb shell dumpsys media.player | grep -A 10 v4l2

  Decoder "c2.v4l2.avc.decoder" supports
    aliases: []
    attributes: 0xa: [
      encoder: 0,
      vendor: 1,
      software-only: 0,
      hw-accelerated: 1 ]
    owner: "codec2::default"
    rank: 128
    profile/levels: [
          1/65536 (Baseline/5.2),
--
  Decoder "c2.v4l2.hevc.decoder" supports
    aliases: []
    attributes: 0xa: [
      encoder: 0,
      vendor: 1,
      software-only: 0,
      hw-accelerated: 1 ]
    owner: "codec2::default"
    rank: 128
    profile/levels: [
          1/524288 (Main/High 5.2),

3.7.2.2. Verbose logcat logging¶

The logs in logcat from v4l2_codec2 are not very verbose by default. To enable more logs, v4l2_codec2 should be rebuild. It’s possible to enable all logs with:

$ cd ~/src/ti-aosp-14/external/v4l2_codec2
$ sed -i 's#//\#define LOG_NDEBUG 0#\#define LOG_NDEBUG 0#' *.cpp