qt_rtmp_demo/media/AACDecoder.cpp

#include "AACDecoder.h"
#include "Debuger.h"


void AACDecoder::OnRtmpFrame(void * dat, uint32_t size)
{
	this->Decode((uint8_t *)dat, size);
}
AACDecoder::AACDecoder() :mObserver(nullptr)
{
	mStatus = RUNNING;
	this->mObserverType = Observer_Audio;
	mCodec = avcodec_find_decoder(AV_CODEC_ID_AAC);
	if (mCodec == NULL) {
		Debuger::Debug(L"find codec fail\r\n");
		mStatus = FAIL;
	}
	mCodecCtx =  avcodec_alloc_context3(mCodec);
	if (nullptr == mCodecCtx) {
		Debuger::Debug(L"find codec ctx fail\r\n");
		mStatus = FAIL;
	}
	mCodecCtx->codec = mCodec;
	mCodecCtx->codec_type = AVMEDIA_TYPE_AUDIO;
	mCodecCtx->sample_rate = 44100;
	mCodecCtx->channels = 2;
	mCodecCtx->channel_layout = AV_CH_LAYOUT_STEREO;
	mCodecCtx->sample_fmt = AV_SAMPLE_FMT_FLTP;
	mCodecCtx->frame_size = 2048;
#if LIBSWRESAMPLE_VERSION_MINOR >= 17	// <20><><EFBFBD>ݰ汾<DDB0><E6B1BE>ͬ<EFBFBD><CDAC>ѡ<EFBFBD><D1A1><EFBFBD>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD><EFBFBD>
	mSwrCtx = swr_alloc();

	av_opt_set_int(mSwrCtx, "in_channel_layout", AV_CH_LAYOUT_STEREO, 0);
	av_opt_set_int(mSwrCtx, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0);
	av_opt_set_int(mSwrCtx, "in_sample_rate", 44100, 0);
	av_opt_set_int(mSwrCtx, "out_sample_rate", 44100, 0);
	av_opt_set_sample_fmt(mSwrCtx, "in_sample_fmt", AV_SAMPLE_FMT_FLTP, 0);
	av_opt_set_sample_fmt(mSwrCtx, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0);
	swr_init(mSwrCtx);

#else
	mSwrCtx = swr_alloc();

	mSwrCtx = swr_alloc_set_opts(mSwrCtx,
		AV_CH_LAYOUT_STEREO,   //output
		AV_SAMPLE_FMT_S16,
		44100,
		AV_CH_LAYOUT_STEREO,    // input
		AV_SAMPLE_FMT_FLTP,
		44100,
		0, NULL);
	swr_init(mSwrCtx);
#endif

	if (avcodec_open2(mCodecCtx, mCodec, NULL) < 0) {
		Debuger::Debug(L"can't open codec\r\n");
		mStatus = FAIL;
	}
	mSampleRate = 44100;
	mChannel = 2;
	mChannelLayout = AV_CH_LAYOUT_STEREO;
	mSampleFmt = AV_SAMPLE_FMT_FLTP;
	mStatus = RUNNING;
	mU16Data = (uint8_t *)av_malloc(192000);
}
#define MAX_AUDIO_FRAME_SIZE  192000

AACDecoder::AACDecoder(AVStream * p):mObserver(nullptr)
{
	mStatus = RUNNING;
	this->mObserverType = Observer_Audio;
	if (nullptr == p) {
		Debuger::Debug(L"find codec fail\r\n");
		mStatus = FAIL;
	}
	mCodecCtx = p->codec;
	mCodec = avcodec_find_decoder(mCodecCtx->codec_id);
	if (mCodec == NULL) {
		Debuger::Debug(L"find codec fail\r\n");
		mStatus = FAIL;
	}
	if (avcodec_open2(mCodecCtx, mCodec, NULL) < 0) {
		Debuger::Debug(L"can't open codec\r\n");
		mStatus = FAIL;
	}
	mSampleRate = mCodecCtx->sample_rate;
	mChannel = mCodecCtx->channels;
	mChannelLayout = mCodecCtx->channel_layout;
	mSampleFmt = mCodecCtx->sample_fmt;
}

int AACDecoder::Decode(uint8_t * dat, uint16_t size)
{
	AVPacket pkt;
	int got_pcm = 0;
	int len = 0;

	if (mStatus == RUNNING) {
		mPcmDat = av_frame_alloc();
		av_init_packet(&pkt);

		char* data = (char*)dat;
		pkt.data = (uint8_t *)data;
		pkt.size = size;

		len = avcodec_decode_audio4(this->mCodecCtx, mPcmDat, &got_pcm, &pkt);
		if (len < 0) {
			printf("Error while decoding a frame.\n");
			return -1;
		}
		if (got_pcm == 0) {
			return 0;
		}
		int buffer_size = av_samples_get_buffer_size(NULL, AV_CH_LAYOUT_STEREO,
			mPcmDat->nb_samples,
			AV_SAMPLE_FMT_S16, 1);

		swr_convert(mSwrCtx, &mU16Data, buffer_size, (const uint8_t **)mPcmDat->data,
			mPcmDat->nb_samples);

		//Debuger::Debug(L"get %d audio samples\r\n", mPcmDat->nb_samples);
		if (nullptr != this->mObserver) {
			int out_buffer_size = av_samples_get_buffer_size(NULL, 2, mPcmDat->nb_samples,
				AV_SAMPLE_FMT_FLTP, 1);
			this->mObserver->OnAudioDecode(mU16Data, buffer_size);
		}
		//(const uint8_t **)mPcmDat->data, mPcmDat->nb_samples;
		av_frame_free(&mPcmDat);
		return 0;
	}
}

int AACDecoder::SetObserver(AACDecoderObserver *p)
{
	if(nullptr != p)
		this->mObserver = p;
	return 0;
}