// ffm_console.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

extern "C" {
#include "ffmpeg/inttypes.h"
#include "ffmpeg/include/libavutil/error.h"
#include "ffmpeg/include/libavutil/samplefmt.h"
#include "ffmpeg/include/libavcodec/avcodec.h"
#include "ffmpeg/include/libavformat/avformat.h"
#include "ffmpeg/include/libavutil/file.h"
#include "ffmpeg/include/libavutil/frame.h"
#include "ffmpeg/include/libswresample/swresample.h"
#include "ffmpeg/include/libavutil/channel_layout.h"
}

AVFormatContext *pFormatCtx;
AVOutputFormat *pOutputFormatCtx;
AVCodecContext *c = NULL;
AVCodec *aCodec;
AVPacket avpkt;
FILE * f;
static SwrContext * swrctx = NULL;

AVFrame *decoded_frame = NULL;

#define AUDIO_INBUF_SIZE 20480
#define AUDIO_REFILL_THRESH 4096

uint8_t buffer[4096 *2];
uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];

int _tmain(int argc, _TCHAR* argv[])
{
	int errcode;
	int ret;

	avcodec_register_all();
	av_register_all();

	const char *filename = "f:\\test.at3";

	if ((errcode = avformat_open_input(&pFormatCtx, filename, NULL, NULL)) < 0)
	{
        char errDescr[4096];
        av_strerror(errcode, errDescr, 4096);
		return -1;
	}

	aCodec = avcodec_find_decoder(AV_CODEC_ID_ATRAC3P);
	if (aCodec == NULL)
		return -1;

	c = pFormatCtx->streams[0]->codec;


	int res = avcodec_open2(c, aCodec, NULL);

	f = fopen("f:\\test.at3", "rb");
    if (!f)
        return -1;

	// ----------------------------------------------------------
	// decode part
	uint8_t sample_buffer[44100];
	int samples = 0;
	uint8_t *out = sample_buffer;

	FILE * outfile = fopen("f:\\output_at3.raw", "wb");
	av_init_packet(&avpkt);

	while (1)
	{

		avpkt.data = inbuf;
		avpkt.size = fread(inbuf, 1, c->block_align, f);

		memset(sample_buffer,0,44100);
		int got_frame = 0;
		if (!decoded_frame)
		{
			if (!(decoded_frame = av_frame_alloc()))
				return -1;
		}

		av_read_frame(pFormatCtx, &avpkt);

		int len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt);
		if (len < 0)
			return -1;

		int64_t def_chans = av_get_default_channel_layout(decoded_frame->channels);
		if (got_frame)
		{
			swrctx = swr_alloc_set_opts(swrctx, AV_CH_LAYOUT_STEREO, AV_SAMPLE_FMT_S16, c->sample_rate, def_chans, c->sample_fmt, c->sample_rate,	0,	NULL);
			if (!swrctx || swr_init(swrctx) < 0)
			{
				avcodec_close(c);
				return -1;
			}

			samples = swr_convert(swrctx, &out, decoded_frame->nb_samples, (const uint8_t**)decoded_frame->extended_data, decoded_frame->nb_samples);
			if (samples < 0)
				return -1;
			swr_free(&swrctx);

			fwrite(sample_buffer,1,decoded_frame->nb_samples * 4,outfile);
		}
	}
	fclose(outfile);
	fclose(f);

	return 0;
}