muxer_mpeg.c

来自「君正早期ucos系统(只有早期的才不没有打包成库),MPLAYER,文件系统,图」· C语言 代码 · 共 2,496 行 · 第 1/5 页

}


static void write_mpeg_rate(int type, unsigned char *b, unsigned int rate) 
{
	rate = ((rate*8)+399) / 400;
	
	if(type == MUX_MPEG1)
	{
		b[0] = ((rate >> 15) & 0x7f) | 0x80;
		b[1] = (rate >> 7) & 0xff;
		b[2] = ((rate << 1) & 0xff) | 1;
	}
	else
	{
		b[0] = (rate >> 14);
		b[1] = (rate >> 6) & 0xff;
		b[2] = ((rate & 0x3f) << 2) | 0x03;	
	}
}


static void write_mpeg_std(unsigned char *b, unsigned int size, unsigned int type, uint8_t mod) 
{
	//type = 0:mpeg audio/128, 1:video and pes private streams (including ac3/dts/lpcm)/1024
	if(type == 0)	//audio
		size = (size + 127) / 128;
	else		//video or other
		size = ((size + 1023) / 1024);

	if(! size)
		size++;

	b[0] = ((size >> 8) & 0x3f) | (type==1 ? 0x60 : 0x40) | mod;
	b[1] = size & 0xff;
}

static void write_mpeg2_scr(unsigned char *b, uint64_t ts) 
{
	uint16_t t1, t2, t3, scr_ext;
	scr_ext = ts % 300ULL;
	ts /= 300ULL;
	ts &= 0x1FFFFFFFFULL;	//33 bits
	t1 = (ts >> 30) & 0x7;;
	t2 = (ts >> 15) & 0x7fff;
	t3 = ts & 0x7fff;
	
	b[0] = (t1 << 3 ) | 0x44 | ((t2 >> 13) & 0x3);
	b[1] = (t2 >> 5);
	b[2] = (t2 & 0x1f) << 3 | 0x4 | ((t3 >> 13) & 0x3);
	b[3] = (t3 >> 5);
	b[4] = (t3 & 0x1f) << 3 | ((scr_ext >> 7) & 0x03) | 0x4;
	b[5] = ((scr_ext << 1) & 0xFF) | 1;
}


static int write_mpeg_pack_header(muxer_t *muxer, char *buff)
{
	int len;
	muxer_priv_t *priv;
	
	priv = (muxer_priv_t *) muxer->priv;
	*(uint32_t *)buff = be2me_32(PACK_HEADER_START_CODE);
	if(priv->mux==MUX_MPEG1)
	{
		write_mpeg_ts(&buff[4], priv->scr, 0x20); // 0010 and SCR
		write_mpeg_rate(priv->mux, &buff[9], muxer->sysrate);
		len = 12;
	}
	else
	{
		write_mpeg2_scr(&buff[4], priv->scr); // 0010 and SCR
		write_mpeg_rate(priv->mux, &buff[10], muxer->sysrate);
		buff[13] = 0xf8; //5 bits reserved + 3 set to 0 to indicate 0 stuffing bytes 
		len = 14;
	}

	return len;
}


static int write_mpeg_system_header(muxer_t *muxer, char *buff)
{
	int len;
	uint8_t i;
	muxer_priv_t *priv;
	priv = (muxer_priv_t *) muxer->priv;
	
	len = 0;
	*(uint32_t *)(&buff[len]) = be2me_32(SYSTEM_HEADER_START_CODE);
	len += 4;
	*(uint16_t *)(&buff[len]) = 0; 	//fake length, we'll fix it later
	len += 2;
	write_mpeg_rate(MUX_MPEG1, &buff[len], muxer->sysrate);
	len += 3;
		
	buff[len++] = 0x4 | (priv->is_xvcd ? 1 : 0); 	//1 audio stream bound, no fixed, CSPS only for xvcd
	//stolen from libavformat
	if(priv->is_xvcd || priv->is_dvd)
		buff[len++] = 0xe1;	//system_audio_lock, system_video_lock, marker, 1 video stream bound
	else
		buff[len++] = 0x21;	//marker, 1 video stream bound
	
	buff[len++] = ((priv->mux == MUX_MPEG1) ? 0xff : 0x7f);	//in mpeg2 there's the packet rate restriction
	
	for(i = 0; i < priv->sys_info.cnt; i++)
	{
		buff[len++] = priv->sys_info.streams[i].id;
		write_mpeg_std(&buff[len], priv->sys_info.streams[i].bufsize, priv->sys_info.streams[i].type, 
			(priv->sys_info.streams[i].type == 1 ? 0xe0: 0xc0));
		len += 2;
	}
	
	*(uint16_t *)(&buff[4]) = be2me_16(len - 6);	// length field fixed
	
	return len;
}

static int write_mpeg_psm(muxer_t *muxer, char *buff)
{
	int len;
	uint8_t i;
	uint16_t dlen;
	muxer_priv_t *priv;
	priv = (muxer_priv_t *) muxer->priv;
	
	len = 0;
	*(uint32_t *)(&buff[len]) = be2me_32(PSM_START_CODE);
	len += 4;
	*(uint16_t *)(&buff[len]) = 0; 	//fake length, we'll fix it later
	len += 2;
	buff[len++] = 0xe0;		//1 current, 2 bits reserved, 5 version 0
	buff[len++] = 0xff;		//7 reserved, 1 marker
	buff[len] = buff[len+1] = 0;	//length  of the program descriptors (unused)
	len += 2;
	*(uint16_t *)(&buff[len]) = 0; //length of the es descriptors
	len += 2;
	
	dlen = 0;
	for(i = 0; i < priv->psm_info.cnt; i++)
	{
		if(
			(priv->psm_info.streams[i].id == 0xbd) || 
			(priv->psm_info.streams[i].id >= 0xe0 && priv->psm_info.streams[i].id <= 0xef) || 
			(priv->psm_info.streams[i].id >= 0xc0 && priv->psm_info.streams[i].id <= 0xcf)
		)
		{
			buff[len++] = priv->psm_info.streams[i].type;
			buff[len++] = priv->psm_info.streams[i].id;
			buff[len++] = 0;	//len of descriptor upper ...
			buff[len++] = 6;	//... lower
			
			//registration descriptor
			buff[len++] = 0x5;	//tag
			buff[len++] = 4;	//length: 4 bytes
			memcpy(&(buff[len]), (char*) &(priv->psm_info.streams[i].format), 4);
			len += 4;
			dlen += 10;
		}
	}
	*(uint16_t *)(&buff[10]) = be2me_16(dlen);	//length of the es descriptors
	
	*(uint16_t *)(&buff[4]) = be2me_16(len - 6 + 4);	// length field fixed, including size of CRC32
	
	*(uint32_t *)(&buff[len]) = be2me_32(CalcCRC32(buff, len));
	
	len += 4;	//for crc
	
	return len;
}

static int write_mpeg_pes_header(muxer_headers_t *h, uint8_t *pes_id, uint8_t *buff, uint16_t plen, int stuffing_len, int mux_type)
{
	int len;
	
	len = 0;
	memcpy(&buff[len], pes_id, 4);
	len += 4;

	buff[len] = buff[len+1] = 0;	//fake len
	len += 2;

	if(mux_type == MUX_MPEG1)
	{
		if(stuffing_len > 0)
		{
			memset(&buff[len], 0xff, stuffing_len);
			len += stuffing_len;
		}
		
		if(h->buffer_size > 0)
		{
			write_mpeg_std(&buff[len], h->buffer_size, h->type, 0x40); // 01 is pes1 format	
			len += 2;
		}
	}
	else	//MPEG2
	{
		buff[len] = (h->pes_is_aligned ? 0x84 : 0x80);	//0x10... 
		len++;
		buff[len] = ((h->buffer_size > 0) ?  1 : 0) | (h->pts ? (h->dts ? 0xC0 : 0x80) : 0);	//pes extension + pts/dts flags
		len++;
		buff[len] = (h->pts ? (h->dts ? 10 : 5) : 0) + ((h->buffer_size > 0) ?  3 : 0) + stuffing_len;//pts + std + stuffing
		len++;
	}
	
	
	if(h->pts)
	{
		write_mpeg_ts(&buff[len], h->pts, (h->dts ? 0x30 : 0x20)); // 001x and both PTS/DTS
		len += 5;
		
		if(h->dts)
		{
			write_mpeg_ts(&buff[len], h->dts, 0x10); // 0001 before DTS
			len += 5;
		}
	}
	else
	{
		if(mux_type == MUX_MPEG1)
		{
			buff[len] = 0x0f;
			len += 1;
		}
	}

	
	if(mux_type == MUX_MPEG2)
	{	
		if(h->buffer_size > 0)
		{
			buff[len] = 0x1e;	//std flag
			len++;
			
			write_mpeg_std(&buff[len], h->buffer_size, h->type, 0x40);
			len += 2;
		}
		
		if(stuffing_len > 0)
		{
			memset(&buff[len], 0xff, stuffing_len);
			len += stuffing_len;
		}
	}

	*((uint16_t*) &buff[4]) = be2me_16(len + plen - 6);	//fix pes packet size	
	return len;
}


static void write_pes_padding(uint8_t *buff, uint16_t len)
{
	//6 header bytes + len-6 0xff chars
	buff[0] = buff[1] = 0;
	buff[2] = 1;
	buff[3] = 0xbe;
	*((uint16_t*) &buff[4]) = be2me_16(len - 6);
	memset(&buff[6], 0xff, len - 6);
}

static void write_psm_block(muxer_t *muxer, stream_t *stream)
{
	uint16_t offset, stuffing_len;
	muxer_priv_t *priv = (muxer_priv_t *) muxer->priv;
	uint8_t *buff = priv->buff;
	
	offset = write_mpeg_pack_header(muxer, buff);
	offset += write_mpeg_psm(muxer, &buff[offset]);
	stuffing_len = priv->packet_size - offset;
	if(stuffing_len > 0)
	{
		//insert a PES padding packet
		write_pes_padding(&buff[offset], stuffing_len);
		offset += stuffing_len;
	}
	stream_write_buffer(stream, buff, offset);
	priv->headers_size += offset;
}


static int write_nav_pack(uint8_t *buff)
{
	// concatenation of pes_private2 + 03d4 x 0 and pes_private2 + 03fa x 0
        int len;

	mp_msg(MSGT_MUXER, MSGL_DBG3, "NAV\n");
	len = 0;
	*(uint32_t *)(&buff[len]) = be2me_32(PES_PRIVATE2);
	len += 4;
	buff[len++] = 0x3;
	buff[len++] = 0xd4;
	memset(&buff[len], 0, 0x03d4);
        len += 0x03d4;

	*(uint32_t *)(&buff[len]) = be2me_32(PES_PRIVATE2);
	len += 4;
	buff[len++] = 0x3;
	buff[len++] = 0xfa;
	memset(&buff[len], 0, 0x03fa);
        len += 0x03fa;

	return len;
}

static uint32_t calc_pes_hlen(int format, muxer_headers_t *h, muxer_priv_t *priv)
{
	uint32_t len;
	
	if(format == MUX_MPEG1)
		len = 6;
	else
		len = 9;
	
	if(h->pts)
	{
		len += 5;
		if(h->dts)
			len += 5;
	}
	else if(format == MUX_MPEG1)
		len += 1;
	
	if(h->buffer_size > 0)
	{
		if(format == MUX_MPEG2)
			len += 3;
		else
			len += 2;
	}

	//len = max(h->min_pes_hlen, len);
	
	return len;
}

	
static int write_mpeg_pack(muxer_t *muxer, muxer_stream_t *s, stream_t *stream, int isoend)
{
	size_t tot, offset;
	muxer_priv_t *priv;
	unsigned char *buff;
	int stuffing_len;

	priv = (muxer_priv_t *) muxer->priv;
	buff = priv->buff;

	if(isoend)
	{
		offset = priv->packet_size - 4;
		write_pes_padding(buff, offset);
		buff[offset + 0] = buff[offset + 1] = 0;
		buff[offset + 2] = 1;
		buff[offset + 3] = 0xb9;
		
		stream_write_buffer(stream, buff, priv->packet_size);
		return 1;
	}
	else	//FAKE DVD NAV PACK
	{
		offset = write_mpeg_pack_header(muxer, buff);
		offset += write_mpeg_system_header(muxer, &buff[offset]);
		
		//priv->update_system_header = 0;
		
		if(priv->is_dvd)
			offset += write_nav_pack(&buff[offset]);
			
		stuffing_len = priv->packet_size - offset;
		if(stuffing_len > 0)
		{
			//insert a PES padding packet
			write_pes_padding(&buff[offset], stuffing_len);
			offset += stuffing_len;
		}
			
		stream_write_buffer(stream, buff, offset);
		priv->headers_size += offset;
		tot = offset;
		muxer->movi_end += tot;
		
		return tot;
	}
}

static void update_demux_bufsize(muxer_headers_t *spriv, uint64_t dts, int framelen, int type)
{
	int dim = (spriv->track_len+16)*sizeof(buffer_track_t);

	if(spriv->track_pos+1 >= spriv->track_len)
	{
		buffer_track_t *tmp = realloc(spriv->buffer_track, dim);
		if(!tmp)
		{
			mp_msg(MSGT_MUXER, MSGL_ERR, "\r\nERROR, couldn't realloc %d bytes for tracking buffer\r\n", dim);
			return;
		}
		spriv->buffer_track = tmp;
		memset(&(spriv->buffer_track[spriv->track_pos+1]), 0, 16*sizeof(buffer_track_t));
		spriv->track_len += 16;
	}

	spriv->buffer_track[spriv->track_pos].size = framelen;
	spriv->buffer_track[spriv->track_pos].dts = dts;	//must be dts

	spriv->track_pos++;
}

static void fix_a52_headers(muxer_stream_t *s)
{
	muxer_headers_t *spriv = s->priv;
	int x = spriv->payload_offset;

	spriv->pack[x+0] = 0x80;
	spriv->pack[x+1] = spriv->frames;
	if(spriv->frames)
	{
		spriv->pack[x+2] = ((spriv->last_frame_rest+1) >> 8) & 0xff;	//256 * 0 ...
		spriv->pack[x+3] = (spriv->last_frame_rest+1) & 0xff;		// + 1 byte(s) to skip
	}
	else
		spriv->pack[x+2] = spriv->pack[x+3] = 0;
}

static inline void remove_frames(muxer_headers_t *spriv, int n)
{
	mpeg_frame_t tmp;
	int i;

	for(i = n; i < spriv->framebuf_used; i++)
	{
		tmp = spriv->framebuf[i - n];
		spriv->framebuf[i - n] = spriv->framebuf[i];
		spriv->framebuf[i] = tmp;
	}
	spriv->framebuf_used -= n;
}

static int calc_packet_len(muxer_stream_t *s, int psize, int finalize)
{
	muxer_headers_t *spriv = s->priv;
	int n, len, frpos, m;

	n = len = 0;
	frpos = spriv->framebuf[0].pos;
	while(len < psize && n < spriv->framebuf_used)
	{
		if(!frpos && len>0 && s->type == MUXER_TYPE_VIDEO && spriv->framebuf[n].type==I_FRAME)
			return len;
		m = FFMIN(spriv->framebuf[n].size - frpos, psize - len);
		len += m;
		frpos += m;
		if(frpos == spriv->framebuf[n].size)
		{
			frpos = 0;
			n++;
		}
	}

	if(len < psize && !finalize)
		return 0;
	return len;
}

static int find_packet_timestamps(muxer_priv_t *priv, muxer_stream_t *s, unsigned int start, uint64_t *dts, uint64_t *pts)
{
	muxer_headers_t *spriv = s->priv;
	int i, m, pes_hlen, ret, threshold;
	uint64_t spts, sdts, dpts;

	if(!spriv->framebuf_used)
		return 0;

	spts = spriv->pts;
	sdts = spriv->dts;
	spriv->dts = spriv->pts = 0;
	ret = 0;
	if(spriv->framebuf[0].pos == 0)	// start of frame
		i = 0;
	else
	{
		pes_hlen = calc_pes_hlen(priv->mux, spriv, priv);

		if(pes_hlen < spriv->min_pes_hlen) 
			pes_hlen = spriv->min_pes_hlen;

		m = spriv->framebuf[0].size - spriv->framebuf[0].pos;

		if(start + pes_hlen + m  >= priv->packet_size)	//spriv->pack_offset
			i = -1;	//this pack won't have a pts: no space available
		else
		{
			if(spriv->framebuf_used < 2)
				goto fail;
			
			if(spriv->framebuf[1].pts == spriv->framebuf[1].dts)
				threshold = 5;
			else
				threshold = 10;