使用ffmpeg库将h264转成mp4的问题

走走刀口 2011-11-15 10:07:16

我使用ffmpeg库将h264格式的转成了mp4格式的视频文件，系统自带的Windows Media Player放不了我转换后的mp4文件，而使用ffmpeg.exe来转的这个h264文件的话，Windows Media Player播放器却能播放，但如果使用暴风影音来播放的话，就能播放出我自己转的mp4文件，请问这个是什么问题？望各位指教，谢谢！



// input file info

AVFormatContext* ic;

AVStream* ist;



// output file info

AVFormatContext* oc;

AVStream* ost;



int m_nBufferSize;

BYTE* m_byBuffer;

// 初始化

nt CConvertManager::Init()

{

	avcodec_register_all();

	avdevice_register_all();

	avfilter_register_all();

	av_register_all();

	return 0;

}

// 处理输入文件

int CConvertManager::AnalyzeInputFile(const char* fileName)

{	

	AVInputFormat* iFormat = NULL;

	AVFormatParameters params, *ap = ¶ms;

	AVCodecContext* icc = NULL;

	AVCodec* codec = NULL;

	int ret;



	ic = avformat_alloc_context();

	if (!ic)

	{

		return -1;

	}



	memset(ap, 0, sizeof(AVFormatParameters));

	ap->prealloced_context = 1;



	// open input file with generic libav function

	ret = av_open_input_file(&ic, fileName, NULL, 0, NULL);

	if (ret < 0)

	{

		return -1;

	}



	// decode the first frames to get the stream parameters

	ret = av_find_stream_info(ic);

	if (ret < 0)

	{

		av_close_input_file(ic);

		return -1;

	}



	videoIndex = -1;

	for (int i = 0; i < ic->nb_streams; i++)

	{

		if (ic->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)

		{

			videoIndex = i;

		}

	}

	if (videoIndex == -1)

	{

		return -1;

	}



	ist = ic->streams[videoIndex];

	icc = ist->codec;

	// find the video encoder

	codec = avcodec_find_decoder(icc->codec_id);



	// open codec

	if (avcodec_open(icc, codec) < 0)

	{

		return -1;

	}



	return 0;

}



// 处理输部门文件

int CConvertManager::AnalyzeOutputFile(const char* fileName)

{

	AVOutputFormat* oFormat = NULL;

	AVFormatParameters params, *ap = ¶ms;

	AVCodecContext* occ = NULL;

	enum CodecID codec_id = CODEC_ID_NONE;

	AVCodec* codec = NULL;

	int ret;



	oFormat = av_guess_format(NULL, fileName, NULL);

	if (!oFormat)

	{

		return -1;

	}

	oc = avformat_alloc_context();

	if (!oc)

	{

		return -1;

	}

	oc->oformat = oFormat;

	strcpy_s(oc->filename, fileName);



	// create video stream

	ost = av_new_stream(oc, 0);

	// guess codec

	codec_id = av_guess_codec(oFormat, NULL, oc->filename, NULL, AVMEDIA_TYPE_VIDEO);

	codec = avcodec_find_encoder(codec_id);



	occ = avcodec_alloc_context();

	av_dict_copy(&ost->metadata, ist->metadata, AV_DICT_DONT_OVERWRITE);

	av_dict_copy(&oc->metadata, ic->metadata, AV_DICT_DONT_OVERWRITE);

	occ = ost->codec;

	occ->codec_id = codec_id;

	occ->codec_type = AVMEDIA_TYPE_VIDEO;

	occ->width = ist->codec->width;

	occ->height = ist->codec->height;

	AVRational rational;

	if (ist->r_frame_rate.num)

	{

		rational.den = ist->r_frame_rate.num;

		rational.num = ist->r_frame_rate.den;

	}

	else

	{

		rational.den = 1;

		rational.num = 25;

	}

	occ->time_base = rational;

	occ->gop_size = ist->codec->gop_size;

	occ->pix_fmt = ist->codec->pix_fmt;

	occ->max_b_frames = ist->codec->max_b_frames;

	occ->bits_per_raw_sample = ist->codec->bits_per_raw_sample;

	occ->chroma_sample_location = ist->codec->chroma_sample_location;

	ost->r_frame_rate = ist->r_frame_rate;

	ost->disposition = ist->disposition;





	// open the file

	ret = avio_open(&oc->pb, fileName, AVIO_FLAG_WRITE);

	if (ret < 0)

	{

		return -1;

	}



	memset(ap, 0, sizeof(AVFormatParameters));

	if (av_set_parameters(oc, NULL) < 0)

	{

		return -1;

	}



	if (avcodec_open(occ, codec)<0)

	{

		return -1;

	}



	return 0;

}



// 格式转换

int CConvertManager::Convert(const char* srcFile, const char* destFile, float rate)

{

	AnalyzeInputFile(srcFile);

	AnalyzeOutputFile(destFile);



	AVFrame *picture = NULL;

	int ret = 0;



	if (ost->codec->codec_type == AVMEDIA_TYPE_VIDEO)

	{

		int size = ost->codec->width * ost->codec->height;

		m_nBufferSize = FFMAX(BUFFER_SIZE, 7*size + 10000);

	}



	if (!m_byBuffer)

	{

		m_byBuffer = (BYTE*)av_malloc(m_nBufferSize);

	}

	if (!m_byBuffer)

	{

		return -1;

	}



	picture = avcodec_alloc_frame();



	// open files and write file headers

	if (av_write_header(oc) < 0)

	{

		return -1;

	}	



	int frameIndex = 0;

	while (ret >= 0)

	{

		memset(m_byBuffer, 0, m_nBufferSize);

		AVPacket packet;

		ret = av_read_frame(ic, &packet);

		if (ret == AVERROR(EAGAIN))

		{

			break;

		}

		if (ret < 0)

		{

			break;

		}

		// is the video stream

		if (packet.stream_index == videoIndex)

		{

			int got_output = 0;

			ret = avcodec_decode_video2(ist->codec, picture, &got_output, &packet);

			if (got_output)

			{

				picture->pts = av_rescale(frameIndex, AV_TIME_BASE*(int64_t)ost->codec->time_base.num, ost->codec->time_base.den);

				picture->pict_type = AV_PICTURE_TYPE_NONE;

				int outSize = avcodec_encode_video(ost->codec, m_byBuffer, m_nBufferSize, picture);

				if (outSize > 0)

				{

					AVPacket pkt;

					av_init_packet(&pkt);

					if (ost->codec->coded_frame && ost->codec->coded_frame->key_frame)

					{

						pkt.flags |= AV_PKT_FLAG_KEY;

					}

					pkt.stream_index = ost->index;

					pkt.data = m_byBuffer;

					pkt.size = outSize;

					ret = av_write_frame(oc, &pkt);

				}

			}

			else

			{

				av_write_frame(oc, &packet);

			}

		}



		frameIndex++;

	}



	// write the trailer

	av_write_trailer(oc);



	return 0;

}