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[英]Android merging mp4 and aac file using mediamuxer mediacodec and mediaextractor (without mp4parser)
[英]Convert PCM to AAC or MP4 file without MediaMuxer
我需要將PCM文件轉換為AAC或MP4文件。 到目前為止,我使用MediaCodec
和MediaMuxer
,但Android 4.3支持MediaMuxer。 有沒有一種方法可以在不使用MediaMuxer
情況下進行轉換?
我的代碼是這樣的:
MediaMuxer mux = null;
try {
File inputFile = new File(filePath + ".pcm");
FileInputStream fis = new FileInputStream(inputFile);
mux = new MediaMuxer(filePath + ".mp4", MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
MediaFormat outputFormat = MediaFormat.createAudioFormat(COMPRESSED_AUDIO_FILE_MIME_TYPE,
SAMPLING_RATE, 1);
outputFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
outputFormat.setInteger(MediaFormat.KEY_BIT_RATE, COMPRESSED_AUDIO_FILE_BIT_RATE);
MediaCodec codec = MediaCodec.createEncoderByType(COMPRESSED_AUDIO_FILE_MIME_TYPE);
codec.configure(outputFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
codec.start();
ByteBuffer[] codecInputBuffers = codec.getInputBuffers();
ByteBuffer[] codecOutputBuffers = codec.getOutputBuffers();
MediaCodec.BufferInfo outBuffInfo = new MediaCodec.BufferInfo();
byte[] tempBuffer = new byte[BUFFER_SIZE];
boolean hasMoreData = true;
double presentationTimeUs = 0;
int audioTrackIdx = 0;
int totalBytesRead = 0;
int percentComplete;
do {
int inputBufIndex = 0;
while (inputBufIndex != -1 && hasMoreData) {
inputBufIndex = codec.dequeueInputBuffer(CODEC_TIMEOUT_IN_MS);
if (inputBufIndex >= 0) {
ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];
dstBuf.clear();
int bytesRead = fis.read(tempBuffer, 0, dstBuf.limit());
if (bytesRead == -1) { // -1 implies EOS
hasMoreData = false;
codec.queueInputBuffer(inputBufIndex, 0, 0, (long) presentationTimeUs, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
} else {
totalBytesRead += bytesRead;
dstBuf.put(tempBuffer, 0, bytesRead);
codec.queueInputBuffer(inputBufIndex, 0, bytesRead, (long) presentationTimeUs, 0);
presentationTimeUs = 1000000l * (totalBytesRead / 2) / SAMPLING_RATE;
}
}
}
// Drain audio
int outputBufIndex = 0;
while (outputBufIndex != MediaCodec.INFO_TRY_AGAIN_LATER) {
outputBufIndex = codec.dequeueOutputBuffer(outBuffInfo, CODEC_TIMEOUT_IN_MS);
if (outputBufIndex >= 0) {
ByteBuffer encodedData = codecOutputBuffers[outputBufIndex];
encodedData.position(outBuffInfo.offset);
encodedData.limit(outBuffInfo.offset + outBuffInfo.size);
if ((outBuffInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0 && outBuffInfo.size != 0) {
codec.releaseOutputBuffer(outputBufIndex, false);
} else {
mux.writeSampleData(audioTrackIdx, codecOutputBuffers[outputBufIndex], outBuffInfo);
codec.releaseOutputBuffer(outputBufIndex, false);
}
} else if (outputBufIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
outputFormat = codec.getOutputFormat();
Log.v("AUDIO", "Output format changed - " + outputFormat);
audioTrackIdx = mux.addTrack(outputFormat);
mux.start();
} else if (outputBufIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
Log.e("AUDIO", "Output buffers changed during encode!");
} else if (outputBufIndex != MediaCodec.INFO_TRY_AGAIN_LATER){
Log.e("AUDIO", "Unknown return code from dequeueOutputBuffer - " + outputBufIndex);
}
}
percentComplete = (int) Math.round(((float) totalBytesRead / (float) inputFile.length()) * 100.0);
Log.v("AUDIO", "Conversion % - " + percentComplete);
} while (outBuffInfo.flags != MediaCodec.BUFFER_FLAG_END_OF_STREAM);
fis.close();
mux.stop();
mux.release();
正如您已經指出的那樣,對於這種工作, 沒有與舊版Android兼容的公共系統API 。
無論如何,您可以使用本機編碼器 (如FFMPEG )來尋求自定義解決方案。 我可以建議你以下: timsu / android-aac-enc
使用漂亮的Java API提取Android Stagefright VO AAC編碼器。
該項目為底層JNI編碼器提供了一個簡單的Java API ,它應該可以使用,因為本機庫已經針對通用ARM體系結構進行了編譯 (請注意,我還沒有測試過它)。 整個圖書館只有500kb,所以它不會給你的APK增加太多。
要進行快速測試,請在項目中導入以下部分:
您應該能夠輕松地將示例調整到您的代碼中。
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