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androidandroid-mediacodec

MediaCodec config passed, but input resolution is actually not supported

I implemented a video encoder by MediaCodec API to encode 2560x720 videos. I verified it on several devices but I encountered a configuration problem on Samsung Note 2 (Android 4.4.2). The following is my code to prepare the codec instance:

Format = MediaFormat.createVideoFormat("video/avc", 2560, 720);
Format.setInteger(MediaFormat.KEY_BIT_RATE, (int) (2560 * 720 * 20 * 0.5f));
Format.setInteger(MediaFormat.KEY_FRAME_RATE, RefreshRate);
Format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar);
Format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 1);

try {
    Codec = MediaCodec.createEncoderByType("video/avc");
    Codec.configure(Format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
    CodecFound = true;
} catch (Exception e) {
    CodecFound = false;
    if(DEBUG) Log.e(CodecTag, "Failed to find available codec", e);
}

No exception is thrown during this try-catch block. But after starting codec operation, neither the encoded data nor the output format is output by the encoder even if the input buffers are filled ("dequeueOutputBuffer" always returns -1). The following is the log after starting codec, where some errors are reported:

05-04 11:29:17.071: E/MFC_ENC(1006): SOMXVE_Init: isSEIOn : 0
05-04 11:29:17.071: E/MFC_ENC_APP(1006): SsbSipMfcEncInit]    IOCTL_MFC_ENC_INIT failed
05-04 11:29:17.111: A/libc(1006): Fatal signal 11 (SIGSEGV) at 0x00000000 (code=1), thread 1403 (AvcEncBufPrc)
05-04 11:29:19.326: E/VideoCodecInfo(1353): Failed to get track format due to codec error
05-04 11:29:25.606: E/ACodec(1353): OMX/mediaserver died, signalling error!
05-04 11:29:25.606: E/MediaCodec(1353): Codec reported an error. (omx error 0x8000100d, internalError -32)
05-04 11:29:25.606: E/AudioService(2462): Media server died.
05-04 11:29:25.606: E/Camera(1353): Error 100

I finally find these commands to get the supported media profile from Note 2

adb shell cat /system/etc/media_codecs.xml

adb shell cat /system/etc/media_profiles.xml

According to the profile list, the max resolution the h264 encoder can support is 1920x1080

<VideoEncoderCap name="h264" enabled="true"
minBitRate="64000" maxBitRate="20000000"
minFrameWidth="176" maxFrameWidth="1920"
minFrameHeight="144" maxFrameHeight="1080"
minFrameRate="1" maxFrameRate="30" />

My questions:

  1. Why the codec can be config successfully with a unacceptable format? Is that a bug or a limitation related to API level?
  2. I heard that there are some APIs for checking this kind of capabilities available from Android 5.0, but I must support 4.4 in my application. Is there any other way to obtain detailed capability info during run-time? (except for parsing the media_profile.xml)

Any help would be really appreciated.

Solution

  • The mediaserver process crashed, apparently due to a null pointer dereference. This process manages all interaction with the media codec hardware. A crash like this indicates a bug in the platform, possibly in the OEM's driver implementation.

    The configure() call should fail if the resolution is not supported. My guess is that this particular implementation has a faulty check.

    I don't think there's a way to check to see if a particular width x height pair works in Android 4.4. You can generally rely on common resolutions like 720p, but some sizes have strange behaviors, especially when you get non-multiples of 16.