Multimedia

The AM62Px has video encoder/decoder: the Chips & Media Wave5.

The wave5 hardware is implemented via:

  • the wave5 driver, located in ${YOUR_PATH}/ti-kernel-aosp/common/drivers/media/platform/chips-media/wave5/

  • a firmware located in ${YOUR_PATH}/ti-aosp-15/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 ${YOUR_PATH}/ti-aosp-15/external/v4l2_codec2.

Testing

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-15
$ source build/envsetup.sh
$ lunch am62p-ap4a-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

Using screenrecord

To test video encoding, we can use the screenrecord command.

$ adb root
$ adb shell 'screenrecord /data/screenrecord.mp4' # Do some screen activity, then hit Ctrl-C
$ adb pull /data/screenrecord.mp4

Tip

screenrecord only records frames when there is some user activity detected. Make sure to generate some activity to avoid empty video files.

Using C2E2ETest.apk

v4l2_codec2 also comes with its own test suite.

  1. Build and install it on the board with:

    $ source build/envsetup.sh
$ lunch am62p-ap4a-userdebug
$ mmm external/v4l2_codec2/tests/c2_e2e_test
$ adb install out/target/product/am62p/testcases/C2E2ETest/arm64/C2E2ETest.apk

# Make sure to give the app storage permissions to read from /sdcard/Downloads
$ adb shell pm grant org.chromium.c2.test android.permission.WRITE_EXTERNAL_STORAGE
$ adb shell pm grant org.chromium.c2.test android.permission.READ_EXTERNAL_STORAGE

  2. Install the test files on the board:

    Download the example file and push it:

    $ adb push videotestsrc_720p.h264 /sdcard/Download/

  3. Run it with:

    $ INPUT=/sdcard/Download/videotestsrc_720p.h264:1280:720:200:258:::1:25
$ OUTPUT=/sdcard/Download/out.raw
# Make sure previous instances are stopped
$ adb shell am force-stop org.chromium.c2.test

# Clear the logs
$ adb shell rm /sdcard/Download/gtest_logs.txt

# Run the test
$ adb shell touch /sdcard/Download/gtest_logs.txt
$ adb shell am start -n org.chromium.c2.test/.E2eTestActivity \
      --ez do-encode false \
      --es log-file "/sdcard/Download/gtest_logs.txt" \
      --esa test-args "--test_video_data=$INPUT","--gtest_filter=C2VideoDecoderByteBufferE2ETest.TestSimpleDecode","--output_frames_path=$OUTPUT"

# View the results
$ adb shell cat /sdcard/Download/gtest_logs.txt

    Tip

    It’s possible to run the software decoder as well to compare. Pass "--use_sw_decoder" to test-args:

    $ adb shell am start -n org.chromium.c2.test/.E2eTestActivity \
      --ez do-encode false \
      --es log-file "/sdcard/Download/gtest_logs.txt" \
      --esa test-args "--test_video_data=$INPUT","--gtest_filter=C2VideoDecoderByteBufferE2ETest.TestSimpleDecode","--output_frames_path=$OUTPUT","--use_sw_decoder"

  4. Then, it’s possible to analyze the result file with tools such as YUVView.

    $ adb pull /sdcard/Download/out.raw
    YUVView

Warning

The per-frame md5 checksum feature is broken. To disable it in code, use the following diff:

diff --git a/tests/c2_e2e_test/jni/video_decoder_e2e_test.cpp b/tests/c2_e2e_test/jni/video_decoder_e2e_test.cpp
index 62589c2818a4..4df27e18e8ed 100644
--- a/tests/c2_e2e_test/jni/video_decoder_e2e_test.cpp
+++ b/tests/c2_e2e_test/jni/video_decoder_e2e_test.cpp

@@ -325,12 +328,14 @@ private:
 TEST_F(C2VideoDecoderByteBufferE2ETest, TestSimpleDecode) {
     VideoFrameValidator video_frame_validator;

+#if 0 // disable MD5 per-frame check, just dump output
     ASSERT_TRUE(video_frame_validator.SetGoldenMD5File(g_env->GoldenMD5FilePath()))
             << "Failed to open MD5 file: " << g_env->GoldenMD5FilePath();

     decoder_->AddOutputBufferReadyCb(std::bind(&VideoFrameValidator::VerifyMD5,
                                                &video_frame_validator, std::placeholders::_1,
                                                std::placeholders::_2, std::placeholders::_3));
+#endif

     if (video_frame_validator.SetOutputFile(g_env->output_frames_path())) {
         decoder_->AddOutputBufferReadyCb(std::bind(&VideoFrameValidator::OutputToFile,

Debugging tips

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),
 --
   Encoder "c2.v4l2.avc.encoder" supports
     aliases: []
     attributes: 0xb: [
       encoder: 1,
       vendor: 1,
       software-only: 0,
       hw-accelerated: 1 ]
     owner: "codec2::default"
     rank: 128
     profile/levels: [
           1/32768 (Baseline/5.1),

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 ${YOUR_PATH}/ti-aosp-15/external/v4l2_codec2
$ sed -i 's#//\#define LOG_NDEBUG 0#\#define LOG_NDEBUG 0#' *.cpp