FFMpegHelper.cpp

gistfile1.cpp

#include "stdafx.h"
#include "FFMpegHelper.h"
#include "get_extradata.h"
#include <iostream>

FFMpegHelper::FFMpegHelper(void)
{
}

FFMpegHelper::~FFMpegHelper(void)
{
}

AVStream *FFMpegHelper::add_audio_stream (AVFormatContext *oc, int codec_id)  
{  
	AVCodecContext * c;  
	AVStream * st;  

	st = av_new_stream (oc , 1);  
	if (! st) {  
		fprintf( stderr, "Could not alloc stream\n" );  
		exit(1);  
	}  

	c = st->codec;  
	c->codec_id = (AVCodecID)codec_id;  
	c->codec_type = AVMEDIA_TYPE_AUDIO ;  

	/* put sample parameters */  
	c->sample_fmt  = AV_SAMPLE_FMT_S16;  
	c->sample_rate = 48000;  
	c->channels    = 2;  
	c->bit_rate    = 448000; //in bits/sec  //@@@@@@@@@@@@@@@@@@@@ this can be customized @@@@@@@@@@@@@@@@@@@@
	c->profile     = FF_PROFILE_AAC_LOW;    //@@@@@@@@@@@@@@@@@@@@ this can be customized @@@@@@@@@@@@@@@@@@@@
	c->channel_layout = AV_CH_LAYOUT_STEREO;//?????? what is this?????

	// some formats want stream headers to be separate  
	if(! strcmp( oc->oformat-> name, "mp4" ) || !strcmp (oc ->oformat ->name , "mov" ) || !strcmp (oc ->oformat ->name , "3gp" ))  
		c->flags |= CODEC_FLAG_GLOBAL_HEADER ;  

	return st;   
}

void FFMpegHelper::open_audio (AVFormatContext *oc, AVStream *st)  
{  
	AVCodecContext * c;  
	AVCodec * codec;  

	c = st-> codec;  

	/* find the audio encoder */  
	//codec = avcodec_find_encoder(c ->codec_id);
	codec = avcodec_find_encoder_by_name("libfdk_aac");
	if (! codec) {  
		fprintf( stderr, "codec not found\n" );  
		exit(1);  
	}  

	/* open it */  
	if ( avcodec_open2( c, codec, NULL) < 0) {  
		fprintf( stderr, "could not open audio codec\n" );  
		exit(1);  
	}  		
}

int FFMpegHelper::init_ffmpeg(mux_ctx_t *pMux_ctx, int VidWidth, int VidHeight, double frame_rate, int profile, int level, bool useAudio)
{
	/* initialize libavcodec, and register all codecs and formats */  
	av_register_all();  
	
	/* auto detect the output format from the name. default is mpeg. */  
	pMux_ctx->fmt = av_guess_format (NULL , pMux_ctx->filename , NULL );  
	if (! pMux_ctx->fmt) {  
		printf( "Could not deduce output format from file extension: using MPEG.\n");  
		pMux_ctx->fmt = av_guess_format ("mpeg" , NULL , NULL );  
	}  

	if (! pMux_ctx->fmt) {  
		fprintf( stderr, "Could not find suitable output format\n" );  
		exit(1);  
	}  

	/* allocate the output media context */  
	pMux_ctx->oc = avformat_alloc_context ();  

	if (! pMux_ctx->oc) {  
		fprintf( stderr, "Memory error\n" );  
		exit(1);  
	}  

	pMux_ctx->oc->oformat = pMux_ctx->fmt;  

	printf("#####################################################\n");
	printf("%s\n", avformat_license());

	pMux_ctx->fmt->video_codec = AV_CODEC_ID_H264; 
	if(useAudio){
		pMux_ctx->fmt->audio_codec = AV_CODEC_ID_AAC;
	}else
	{
		pMux_ctx->fmt->audio_codec = AV_CODEC_ID_NONE;
	}

	_snprintf( pMux_ctx->oc->filename, sizeof( pMux_ctx->oc->filename), "%s" , pMux_ctx->filename );  

	/* add the audio and video streams using the default format codecs 
	and initialize the codecs */  
	pMux_ctx->video_st = NULL;  
	if ( pMux_ctx->fmt->video_codec != CODEC_ID_NONE ) 
	{  
		AVCodecContext * c;  

		pMux_ctx->video_st = av_new_stream (pMux_ctx->oc , 0);  
		
		if (! pMux_ctx->video_st) 
		{  
			fprintf( stderr, "Could not alloc video_stream\n" );  
			exit(1);  
		}  

		c = pMux_ctx->video_st->codec;  
		c->codec_id = ( AVCodecID) pMux_ctx->fmt->video_codec;  
		c->codec_type = AVMEDIA_TYPE_VIDEO ;  

		c->me_range = 2048;   
		c->max_qdiff = 51;   
		
		/* resolution muvideo_st be a multiple of two */  
		c->width = VidWidth;  
		c->height = VidHeight;  
		
		c->time_base.num = 1000000; 
		c->time_base.den = 1000000*(int)frame_rate;  
		
		c->pix_fmt = AV_PIX_FMT_YUV420P ;  

		//#############################
		c->extradata = (uint8_t*)av_mallocz(100);//100bytes must be plenty for extradata
		encFrame_t encFrame;	
		encFrame.frame_height                      = VidHeight;
		encFrame.frame_width                       = VidWidth;
		encFrame.useHighProfile                    = profile == 2;
		encFrame.level                             = level;
		encFrame.PQIndex                           = 10;//junk start qp
		get_extradata((char *)c->extradata, &c->extradata_size, &encFrame);
		//#############################
		
		if ( c->codec_id == CODEC_ID_MPEG2VIDEO ) {  
			/* juvideo_st for tevideo_sting, we also add B frames */  
			c->max_b_frames = 2;  
		}  
		if ( c->codec_id == CODEC_ID_MPEG1VIDEO ){  
			/* Needed to avoid using macroblocks in which some coeffs overflow. 
			This does not happen with normal video, it juvideo_st happens here as 
			the motion of the chroma plane does not match the luma plane. */  
			c->mb_decision =2;  
		}  

		// some formats want video_stream headers to be separate  
		if(! strcmp( pMux_ctx->oc->oformat-> name, "mp4" ) || !strcmp (pMux_ctx->oc ->oformat ->name , "mov" ) || !strcmp (pMux_ctx->oc ->oformat ->name , "3gp" ))  
			c->flags |= CODEC_FLAG_GLOBAL_HEADER ;  
	}  


	/* now that all the parameters are set, we can open the audio and 
	video codecs and allocate the necessary encode buffers */  
	//if ( pMux_ctx->video_st)  
	if(0)
	{
		AVCodec * codec;  
		/* find the video encoder */  
		codec = avcodec_find_encoder (pMux_ctx->video_st->codec->codec_id );  
		if (! codec) {  
			fprintf( stderr, "Video codec not found\n" );  
			exit(1);  
		}  

		/* open the codec */  
		if ( avcodec_open2( pMux_ctx->video_st->codec, codec, NULL) < 0) {  
			fprintf( stderr, "could not open video codec\n" );  
			exit(1);  
		}  	
	}
	
	/* open the output file */  
	if (!( pMux_ctx->fmt-> flags & AVFMT_NOFILE )) {  
		if ( avio_open(&pMux_ctx->oc->pb, pMux_ctx->filename, AVIO_FLAG_WRITE) < 0) {  
			fprintf( stderr, "Could not open '%s'\n" , pMux_ctx->filename );  
			exit(1);  
		}  
	}

	if ( pMux_ctx->fmt->audio_codec != CODEC_ID_NONE ) 
	{  
		pMux_ctx->audio_st           = add_audio_stream (pMux_ctx->oc, pMux_ctx->fmt->audio_codec );  
		pMux_ctx->audio_outbuf_size  = FF_MIN_BUFFER_SIZE * 10;
		pMux_ctx->audio_outbuf       = (uint8_t *)av_malloc(pMux_ctx->audio_outbuf_size);
	} 

	if ( pMux_ctx->audio_st) 
	{
		open_audio( pMux_ctx->oc, pMux_ctx->audio_st);  
	}

	/* write the stream header, if any */  
	if( avformat_write_header (pMux_ctx->oc, NULL ) < 0)  
	{  
		fprintf( stderr, "Could not write header for output file\n" );  
		return -1;  
	}  

	return 0;
}

int FFMpegHelper::close_ffmpeg(mux_ctx_t *pMux_ctx)
{
	int i;

	/* close each codec */  
	if ( pMux_ctx->video_st)  
	{
		avcodec_close( pMux_ctx->video_st->codec);   
	}

	if ( pMux_ctx->audio_st)  
	{
		avcodec_close( pMux_ctx->audio_st->codec);   
		av_free( pMux_ctx->audio_outbuf ); 
	}
		
	/* write the trailer, if any */  
	int res = av_write_trailer (pMux_ctx->oc );  

	/* free the streams */  
	for( i = 0; i < (int)pMux_ctx->oc->nb_streams; i++) {  
		av_freep(& pMux_ctx->oc->streams[ i]-> codec);  
		av_freep(& pMux_ctx->oc->streams[ i]);  
	}  

	if (!( pMux_ctx->fmt-> flags & AVFMT_NOFILE )) {  
		/* close the output file */  
		avio_close( pMux_ctx->oc->pb);  
	}  

	/* free the stream */  
	av_free( pMux_ctx->oc);  

	return 0;
}