WebRTC: H.264 On Non-Qualcomm Android Devices

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User might expiring SDP failure on non-Qualcomm/SAMSUNG chip Android devices when received SDP from another peer that only support H.264. This was caused by a limitation of Android WebRTC SDK that it will check H.264 capabilities via a chip whitelist, which only has Qualcomm and Exynos listed. To make it available for other Android devices, we need to modify and recompile WebRTC Android SDK.

Fetch Code And Test Build

WebRTC: Compile Native WebRTC Android SDK

Modifications

Original code in HardwareVideoEncoderFactory.java:

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private boolean isHardwareSupportedInCurrentSdkH264(MediaCodecInfo info) {
  // First, H264 hardware might perform poorly on this model.
  if (H264_HW_EXCEPTION_MODELS.contains(Build.MODEL)) {
    return false;
  }
  String name = info.getName();
  // QCOM H264 encoder is supported in KITKAT or later.
  return (name.startsWith(QCOM_PREFIX) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT)
      // Exynos H264 encoder is supported in LOLLIPOP or later.
      || (name.startsWith(EXYNOS_PREFIX)
              && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
}

You could add your chips into whitelist here, but it might be easier to remove whitelist check if your target devices is running Android 5.0+(LOLLIPOP), since basically all chips in Android devices support H.264 nowadays.

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private boolean isHardwareSupportedInCurrentSdkH264(MediaCodecInfo info) {
  // First, H264 hardware might perform poorly on this model.
  if (H264_HW_EXCEPTION_MODELS.contains(Build.MODEL)) {
    return false;
  }
  return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
}

Same modifications should be added into MediaCodecVideoDecoderFactory.java as well.
Original code in MediaCodecVideoDecoderFactory.java:

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private boolean isH264HighProfileSupported(MediaCodecInfo info) {
  String name = info.getName();
  // Support H.264 HP decoding on QCOM chips for Android L and above.
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && name.startsWith(QCOM_PREFIX)) {
    return true;
  }
  // Support H.264 HP decoding on Exynos chips for Android M and above.
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && name.startsWith(EXYNOS_PREFIX)) {
    return true;
  }
  return false;
}

modified:

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private boolean isH264HighProfileSupported(MediaCodecInfo info) {
  return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
}

Then recompile SDK by following Fetch Code And Test Build.