mpv/libmpdemux/demux_real.c

/*
    Real parser & demuxer
    
    (C) Alex Beregszaszi <alex@naxine.org>
    
    Based on FFmpeg's libav/rm.c.
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "config.h"
#include "mp_msg.h"
#include "help_mp.h"

#include "stream.h"
#include "demuxer.h"
#include "stheader.h"
#include "bswap.h"

#define MKTAG(a, b, c, d) (a | (b << 8) | (c << 16) | (d << 24))

#define MAX_STREAMS 10

typedef struct {
    int		num_of_packets;
    int		last_a_stream;
    int 	a_streams[MAX_STREAMS];
    int		last_v_stream;
    int 	v_streams[MAX_STREAMS];
} real_priv_t;

static void get_str(int isbyte, demuxer_t *demuxer, char *buf, int buf_size)
{
    int len, i;
    char *q;
    
    if (isbyte)
	len = stream_read_char(demuxer->stream);
    else
	len = stream_read_word(demuxer->stream);
#if 1
    q = buf;
    for (i = 0; i < len; i++)
	if (i < (buf_size - 1))
	    *q++ = stream_read_char(demuxer->stream);
    *q = 0;
#else
    stream_read(demuxer->stream, buf, buf_size);
#endif
}

static void skip_str(int isbyte, demuxer_t *demuxer)
{
    int len;

    if (isbyte)
	len = stream_read_char(demuxer->stream);
    else
	len = stream_read_word(demuxer->stream);

    stream_skip(demuxer->stream, len);    

    printf("skip_str: %d bytes skipped\n", len);
}

int real_check_file(demuxer_t* demuxer){
    real_priv_t *priv;
    int c;

    mp_msg(MSGT_DEMUX,MSGL_V,"Checking for REAL\n");
    
    c = stream_read_dword_le(demuxer->stream);
    if (c == -256)
	return 0; /* EOF */
    if (c != MKTAG('.', 'R', 'M', 'F'))
	return 0; /* bad magic */

    priv = malloc(sizeof(real_priv_t));
    memset(priv, 0, sizeof(real_priv_t));
    demuxer->priv = priv;

    return 1;
}

// return value:
//     0 = EOF or no stream found
//     1 = successfully read a packet
int demux_real_fill_buffer(demuxer_t *demuxer)
{
    real_priv_t *priv = demuxer->priv;
    demux_stream_t *ds = NULL;
    int len;
    int timestamp;
    int stream_id;
    int i;

//    printf("num_of_packets: %d\n", priv->num_of_packets);

loop:
    if (priv->num_of_packets == 0)
	return 0; /* EOF */
    stream_skip(demuxer->stream, 2);
    len = stream_read_word(demuxer->stream);
    if (len == -256) /* EOF */
	return 0;
    if (len < 12)
    {
	printf("bad packet len (%d)\n", len);
	stream_skip(demuxer->stream, len);
	goto loop;
//	return 0; /* bad packet */
    }
    stream_id = stream_read_word(demuxer->stream);
    timestamp = stream_read_dword(demuxer->stream);

//    printf("packet: len: %d, stream_id: %d, timestamp: %d\n",
//	len, stream_id, timestamp);
    
    stream_skip(demuxer->stream, 1); /* reserved */
    stream_skip(demuxer->stream, 1); /* flags */

    priv->num_of_packets--;
    len -= 12;    

    /* check if stream_id is audio stream */
    for (i = 0; i < priv->last_a_stream; i++)
    {
	if (priv->a_streams[i] == stream_id)
	{
//	    printf("packet is audio (id: %d)\n", stream_id);
	    ds = demuxer->audio; /* FIXME */
	    break;
	}
    }
    /* check if stream_id is video stream */
    for (i = 0; i < priv->last_v_stream; i++)
    {
	if (priv->v_streams[i] == stream_id)
	{
//	    printf("packet is video (id: %d)\n", stream_id);
	    ds = demuxer->video; /* FIXME */
	    break;
	}
    }

    /* id not found */
    if (ds == NULL)
    {
	printf("unknown stream id (%d)\n", stream_id);
	stream_skip(demuxer->stream, len);
	goto loop;	
    }

    demuxer->filepos = stream_tell(demuxer->stream);
    ds_read_packet(ds, demuxer->stream, len, timestamp/90000.0f, demuxer->filepos, 0);

    return 1;
}

void demux_open_real(demuxer_t* demuxer)
{
    real_priv_t* priv = demuxer->priv;
    int num_of_headers;
    int i;

    stream_skip(demuxer->stream, 4); /* header size */
    stream_skip(demuxer->stream, 2);
    stream_skip(demuxer->stream, 4);
    num_of_headers = stream_read_dword(demuxer->stream);
//    stream_skip(demuxer->stream, 4); /* number of headers */

    /* parse chunks */
    for (i = 1; i < num_of_headers; i++)
    {
	int chunk, chunk_size;
	
	chunk = stream_read_dword_le(demuxer->stream);
	chunk_size = stream_read_dword(demuxer->stream);

	stream_skip(demuxer->stream, 2);
	
	if (chunk_size < 10)
	    goto fail;
	
	printf("Chunk: %.4s (size: %d)\n",
	    (char *)&chunk, chunk_size);
	
	switch(chunk)
	{
	    case MKTAG('P', 'R', 'O', 'P'):
		printf("Properties chunk\n");
		stream_skip(demuxer->stream, 4); /* max bitrate */
		stream_skip(demuxer->stream, 4); /* avg bitrate */
		stream_skip(demuxer->stream, 4); /* max packet size */
		stream_skip(demuxer->stream, 4); /* avg packet size */
		stream_skip(demuxer->stream, 4); /* nb packets */
		stream_skip(demuxer->stream, 4); /* duration */
		stream_skip(demuxer->stream, 4); /* preroll */
		stream_skip(demuxer->stream, 4); /* index offset */
		stream_skip(demuxer->stream, 4); /* data offset */
		stream_skip(demuxer->stream, 2); /* nb streams */
		stream_skip(demuxer->stream, 2); /* flags */
		break;
	    case MKTAG('C', 'O', 'N', 'T'):
		printf("Broadcasting informations (title, author, copyright, comment)\n");
		skip_str(0, demuxer);	/* title */
		skip_str(0, demuxer);	/* author */
		skip_str(0, demuxer);	/* copyright */
		skip_str(0, demuxer);	/* comment */
		break;
	    case MKTAG('M', 'D', 'P', 'R'):
	    {
		/* new stream */
		int stream_id;
		int bitrate;
		int codec_data_size;
		int codec_pos;
		int v;

		stream_id = stream_read_word(demuxer->stream);
		printf("Found new stream (id: %d)\n", stream_id);
		
		stream_skip(demuxer->stream, 4); /* max bitrate */
		bitrate = stream_read_dword(demuxer->stream); /* bitrate */
		stream_skip(demuxer->stream, 4); /* max packet size */
		stream_skip(demuxer->stream, 4); /* avg packet size */
		stream_skip(demuxer->stream, 4); /* start time */
		stream_skip(demuxer->stream, 4); /* preroll */
		stream_skip(demuxer->stream, 4); /* duration */
		
		skip_str(1, demuxer);	/* stream description */
		skip_str(1, demuxer);	/* mimetype */
		
		codec_data_size = stream_read_dword(demuxer->stream);
		codec_pos = stream_tell(demuxer->stream);

		v = stream_read_dword(demuxer->stream);
		if (v == MKTAG(0xfd, 'a', 'r', '.')) /* audio header */
		{
		    sh_audio_t *sh = new_sh_audio(demuxer, stream_id);

		    printf("Found audio stream!\n");
		    stream_skip(demuxer->stream, 4); /* version */
		    stream_skip(demuxer->stream, 4); /* .ra4 */
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 2);
		    stream_skip(demuxer->stream, 4); /* header size */
		    stream_skip(demuxer->stream, 2); /* add codec info */
		    stream_skip(demuxer->stream, 4); /* coded frame size */
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 2); /* 1 */
		    stream_skip(demuxer->stream, 2); /* coded frame size */
		    stream_skip(demuxer->stream, 4);

		    sh->samplerate = stream_read_word(demuxer->stream);
		    stream_skip(demuxer->stream, 4);
		    sh->channels = stream_read_word(demuxer->stream);
		
		    {
			char buf[128];
			
			get_str(1, demuxer, buf, sizeof(buf));
			get_str(1, demuxer, buf, sizeof(buf));

			v = 0; /* not supported audio codec */
			if (!strcmp(buf, "dnet"))
			{
			    printf("Found AC3 audio\n");
			    sh->format = 0x2000; /* ac3 */
			    v = 1;
			}
		    }
//		    skip_str(1, demuxer); /* desc */
//		    skip_str(1, demuxer); /* desc */
			
		    /* the audio codec name is stored in desc */
		    /* available codecs: DNET -> ac3 */
//		    sh->format = 0x2000; /* ac3 */

		    if (v)
		    {
		    printf("Audio codec: 0x%x\n", sh->format);
		    /* insert as stream */
		    demuxer->audio->sh = sh;
		    sh->ds = demuxer->audio;
		    demuxer->audio->id = stream_id;
		    
		    if (priv->last_a_stream+1 < MAX_STREAMS)
		    {
			priv->a_streams[priv->last_a_stream] = stream_id;
			priv->last_a_stream++;
		    }
		    }
		}
		else
		{
		    /* video header */
		    sh_video_t *sh = new_sh_video(demuxer, stream_id);

		    v = stream_read_dword_le(demuxer->stream);
		    printf("video: %.4s (%x)\n", (char *)&v, v);
		    if (v != MKTAG('V', 'I', 'D', 'O'))
		    {
			mp_msg(MSGT_DEMUX, MSGL_ERR, "Unsupported video codec\n");
			goto skip_this_chunk;
		    }
		    
		    sh->format = stream_read_dword_le(demuxer->stream); /* fourcc */
		    printf("video fourcc: %.4s (%x)\n", (char *)&sh->format, sh->format);

		    // emulate BITMAPINFOHEADER:
		    sh->bih = malloc(sizeof(BITMAPINFOHEADER));
		    memset(sh->bih, 0, sizeof(BITMAPINFOHEADER));
	    	    sh->bih->biSize = 40;
		    sh->disp_w = sh->bih->biWidth = stream_read_word(demuxer->stream);
		    sh->disp_h = sh->bih->biHeight = stream_read_word(demuxer->stream);
		    sh->bih->biPlanes = 1;
		    sh->bih->biBitCount = 24;
		    sh->bih->biCompression = sh->format;
		    sh->bih->biSizeImage= sh->bih->biWidth*sh->bih->biHeight*3;

		    sh->fps = stream_read_word(demuxer->stream);
		    sh->frametime = 1.0f/sh->fps;
		    
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 2);
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 2);

		    /* h263 hack */
		    v = stream_read_dword(demuxer->stream);
		    switch (v)
		    {
			case 0x10000000:
			    /* sub id: 0 */
			    /* codec id: rv10 */
			    break;
			case 0x10003000:
			case 0x10003001:
			    /* sub id: 3 */
			    /* codec id: rv10 */
			    break;
			case 0x20001000:
			    /* codec id: rv20 */
			    break;
			default:
			    /* codec id: none */
		    }
		        
		    /* insert as stream */
		    demuxer->video->sh = sh;
		    sh->ds = demuxer->video;
		    demuxer->video->id = stream_id;
		    if (priv->last_v_stream+1 < MAX_STREAMS)
		    {
			priv->v_streams[priv->last_v_stream] = stream_id;
			priv->last_v_stream++;
		    }
		}

skip_this_chunk:
		/* skip codec info */
		v = stream_tell(demuxer->stream) - codec_pos;
		stream_skip(demuxer->stream, codec_data_size - v);		    
		break;
	    }
	    case MKTAG('D', 'A', 'T', 'A'):
		goto header_end;
	    default:
		printf("Unknown chunk: %x\n", chunk);
		stream_skip(demuxer->stream, chunk_size - 10);
		break;
	}
    }

header_end:
    priv->num_of_packets = stream_read_dword(demuxer->stream);
//    stream_skip(demuxer->stream, 4); /* number of packets */
    stream_skip(demuxer->stream, 4); /* next data header */

    printf("Packets in file: %d\n", priv->num_of_packets);

    /* disable seeking */
    demuxer->seekable = 0;

fail:
    return;
}

void demux_close_real(demuxer_t *demuxer)
{
    real_priv_t* priv = demuxer->priv;
 
    if (priv)
	free(priv);

    return;
}