参考Aegonis的工作1和工作2,我也得到了H.264流,但颜色不正确。我正在使用HTC Butterfly进行开发。这是我的部分代码:
相机:
parameters.setPreviewSize(width, height);
parameters.setPreviewFormat(ImageFormat.YV12);
parameters.setPreviewFrameRate(frameRate);
媒体编解码器:
mediaCodec = MediaCodec.createEncoderByType("video/avc");
MediaFormat mediaFormat = MediaFormat.createVideoFormat("video/avc", 320, 240);
mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, 500000);
mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, 15);
mediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar);
mediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
mediaCodec.configure(mediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mediaCodec.start();
当使用COLOR_FormatYUV420Planar时,会出现错误提示“[OMX.qcom.video.encoder.avc]不支持颜色格式19”,因此我只能使用COLOR_FormatYUV420SemiPlanar。有人知道为什么不支持吗?
明白了,通过使用:
int colorFormat = 0;
MediaCodecInfo.CodecCapabilities capabilities = codecInfo.getCapabilitiesForType(mimeType);
for (int i = 0; i < capabilities.colorFormats.length && colorFormat == 0; i++) {
int format = capabilities.colorFormats[i];
Log.e(TAG, "Using color format " + format);
}
我们可以有颜色格式 21 (COLOR_FormatYUV420SemiPlanar) 和 2130708361 (没有对应的格式),我认为格式会因设备而异。
然后,我尝试了从 work 1 和 work 2 中提供的建议中进行的颜色转换:
public static byte[] YV12toYUV420PackedSemiPlanar(final byte[] input, final byte[] output, final int width, final int height) {
/*
* COLOR_TI_FormatYUV420PackedSemiPlanar is NV12
* We convert by putting the corresponding U and V bytes together (interleaved).
*/
final int frameSize = width * height;
final int qFrameSize = frameSize/4;
System.arraycopy(input, 0, output, 0, frameSize); // Y
for (int i = 0; i < qFrameSize; i++) {
output[frameSize + i*2] = input[frameSize + i + qFrameSize]; // Cb (U)
output[frameSize + i*2 + 1] = input[frameSize + i]; // Cr (V)
}
return output;
}
public static byte[] YV12toYUV420Planar(byte[] input, byte[] output, int width, int height) {
/*
* COLOR_FormatYUV420Planar is I420 which is like YV12, but with U and V reversed.
* So we just have to reverse U and V.
*/
final int frameSize = width * height;
final int qFrameSize = frameSize/4;
System.arraycopy(input, 0, output, 0, frameSize); // Y
System.arraycopy(input, frameSize, output, frameSize + qFrameSize, qFrameSize); // Cr (V)
System.arraycopy(input, frameSize + qFrameSize, output, frameSize, qFrameSize); // Cb (U)
return output;
}
public static byte[] swapYV12toI420(byte[] yv12bytes, int width, int height) {
byte[] i420bytes = new byte[yv12bytes.length];
for (int i = 0; i < width*height; i++)
i420bytes[i] = yv12bytes[i];
for (int i = width*height; i < width*height + (width/2*height/2); i++)
i420bytes[i] = yv12bytes[i + (width/2*height/2)];
for (int i = width*height + (width/2*height/2); i < width*height + 2*(width/2*height/2); i++)
i420bytes[i] = yv12bytes[i - (width/2*height/2)];
return i420bytes;
}
显然,YV12toYUV420PackedSemiPlanar 的颜色转换比其他两种方法表现更好。它相对来说更好,但与真实颜色相比仍然有所不同。我的代码是否有问题?欢迎留言评论。
YV12toYUV420PackedSemiPlanar
以交换Cb/Cr通道,它看起来是否正确?) - fadden