mpv/libmpdemux/demux_real.c

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

    TODO: fix the whole syncing mechanism
    
    $Log$
    Revision 1.10  2002/04/24 15:36:06  albeu
    Added demuxer uninit

    Revision 1.9  2002/03/15 15:51:37  alex
    added PRE-ALPHA seeking ability and index table generator (like avi's one)

    Revision 1.8  2002/01/23 19:41:01  alex
    fixed num_of_packets and current_packet handling, bug found by Mike Melanson

    Revision 1.7  2002/01/18 11:02:52  alex
    fix dnet support

    Revision 1.6  2002/01/04 19:32:58  alex
    updated/extended some parts, based on RMFF (also initial ATRAC3 hackings and notes)


Audio codecs: (supported by RealPlayer8 for Linux)
    ATRC - RealAudio 8 (ATRAC3) - www.minidisc.org/atrac3_article.pdf,
           ACM decoder uploaded, needs some fine-tuning to work
    COOK/COKR - RealAudio G2
    DNET - RealAudio 3.0, really it's AC3 in swapped-byteorder
    SIPR - SiproLab's audio codec, ACELP decoder working with MPlayer,
	   needs fine-tuning too :)

Video codecs: (supported by RealPlayer8 for Linux)
    RV10 - H.263 based, working with libavcodec's decoder
    RV20
    RV30
*/

#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 32

typedef struct {
    int		timestamp;
    int		offset;
    int		packetno;
    int		len; /* only filled by our index generator */
    int		flags; /* only filled by our index generator */
} real_index_table_t;

typedef struct {
    /* for seeking */
    int		index_chunk_offset;
    real_index_table_t *index_table[MAX_STREAMS];
//    int		*index_table[MAX_STREAMS];
    int		index_table_size[MAX_STREAMS];
    int		data_chunk_offset;
    int		num_of_packets;
    int		current_packet;

    int		current_aid;
    int		current_vid;
    int		current_apacket;
    int		current_vpacket;
    
    /* stream id table */
    int		last_a_stream;
    int 	a_streams[MAX_STREAMS];
    int		last_v_stream;
    int 	v_streams[MAX_STREAMS];
} real_priv_t;

/* originally from FFmpeg */
static void get_str(int isbyte, demuxer_t *demuxer, char *buf, int buf_size)
{
    int len;
    
    if (isbyte)
	len = stream_read_char(demuxer->stream);
    else
	len = stream_read_word(demuxer->stream);

    stream_read(demuxer->stream, buf, (len > buf_size) ? buf_size : len);
    if (len > buf_size)
	stream_skip(demuxer->stream, len-buf_size);

    printf("read_str: %d bytes read\n", len);
}

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);
}

static void dump_index(demuxer_t *demuxer, int stream_id)
{
    real_priv_t *priv = demuxer->priv;
    real_index_table_t *index;
    int i, entries;

    if (!verbose)
	return;
    
    if (stream_id > MAX_STREAMS)
	return;

    index = priv->index_table[stream_id];
    entries = priv->index_table_size[stream_id];
    
    printf("Index table for stream %d\n", stream_id);
    for (i = 0; i < entries; i++)
    {
	printf("packetno: %x pos: %x len: %x timestamp: %x flags: %x\n",
	    index[i].packetno, index[i].offset, index[i].len, index[i].timestamp,
	    index[i].flags);
    }
}

static int parse_index_chunk(demuxer_t *demuxer)
{
    real_priv_t *priv = demuxer->priv;
    int origpos = stream_tell(demuxer->stream);
    int next_header_pos = priv->index_chunk_offset;
    int i, entries, stream_id;

read_index:
    stream_seek(demuxer->stream, next_header_pos);

    i = stream_read_dword_le(demuxer->stream);
    if ((i == -256) || (i != MKTAG('I', 'N', 'D', 'X')))
    {
	printf("Something went wrong, no index chunk found on given address (%d)\n",
	    next_header_pos);
	goto end;
    }

    printf("Reading index table from index chunk (%d)\n",
	next_header_pos);

    i = stream_read_dword(demuxer->stream);
    printf("size: %d bytes\n", i);

    i = stream_read_word(demuxer->stream);
    if (i != 0)
	printf("Hmm, index table with unknown version (%d), please report it to MPlayer developers!\n", i);

    entries = stream_read_dword(demuxer->stream);
    printf("entries: %d\n", entries);
    
    stream_id = stream_read_word(demuxer->stream);
    printf("stream_id: %d\n", stream_id);
    
    next_header_pos = stream_read_dword(demuxer->stream);
    printf("next_header_pos: %d\n", next_header_pos);
    if (entries <= 0)
    {
	if (next_header_pos)
	    goto read_index;
	i = entries;
	goto end;
    }

    priv->index_table_size[stream_id] = entries;
    priv->index_table[stream_id] = malloc(priv->index_table_size[stream_id] * sizeof(real_index_table_t));
    
    for (i = 0; i < entries; i++)
    {
	stream_skip(demuxer->stream, 2); /* version */
	priv->index_table[stream_id][i].timestamp = stream_read_dword(demuxer->stream);
	priv->index_table[stream_id][i].offset = stream_read_dword(demuxer->stream);
	priv->index_table[stream_id][i].packetno = stream_read_dword(demuxer->stream);
//	printf("Index table: Stream#%d: entry: %d: pos: %d\n",
//	    stream_id, i, priv->index_table[stream_id][i].offset);
    }
    
    dump_index(demuxer, stream_id);

    if (next_header_pos > 0)
	goto read_index;

end:
    demuxer->seekable = 1; /* got index, we're able to seek */
    if (i == -256)
	stream_reset(demuxer->stream);
    stream_seek(demuxer->stream, origpos);
    if (i == -256)
	return 0;
    else
	return 1;
}

static int generate_index(demuxer_t *demuxer)
{
    real_priv_t *priv = demuxer->priv;
    int origpos = stream_tell(demuxer->stream);
    int data_pos = priv->data_chunk_offset-10;
    int num_of_packets = 0;
    int i, entries = 0;
    int len, stream_id = 0, timestamp, flags;
    int tab_pos = 0;

read_index:
    stream_seek(demuxer->stream, data_pos);

    i = stream_read_dword_le(demuxer->stream);
    if ((i == -256) || (i != MKTAG('D', 'A', 'T', 'A')))
    {
	printf("Something went wrong, no data chunk found on given address (%d)\n",
	    data_pos);
	goto end;
    }
    stream_skip(demuxer->stream, 4); /* chunk size */
    stream_skip(demuxer->stream, 2); /* version */
    
    num_of_packets = stream_read_dword(demuxer->stream);
    printf("Generating index table from raw data (pos: 0x%x) for %d packets\n",
	data_pos, num_of_packets);

    data_pos = stream_read_dword_le(demuxer->stream)-10; /* next data chunk */

    for (i = 0; i < MAX_STREAMS; i++)
    {
    priv->index_table_size[i] = num_of_packets;
    priv->index_table[i] = malloc(priv->index_table_size[i] * sizeof(real_index_table_t));
//    priv->index_table[stream_id] = realloc(priv->index_table[stream_id],
//	priv->index_table_size[stream_id] * sizeof(real_index_table_t));
    }

    tab_pos = 0;
    
//    memset(priv->index_table_size, 0, sizeof(int)*MAX_STREAMS);
//    memset(priv->index_table, 0, sizeof(real_index_table_t)*MAX_STREAMS);
    
    while (tab_pos < num_of_packets)
    {
    i = stream_read_char(demuxer->stream);
    if (i == -256)
	goto end;
    stream_skip(demuxer->stream, 1);
//    stream_skip(demuxer->stream, 2); /* version */

    len = stream_read_word(demuxer->stream);
    stream_id = stream_read_word(demuxer->stream);
    timestamp = stream_read_dword(demuxer->stream);
    
    stream_skip(demuxer->stream, 1); /* reserved */
    flags = stream_read_char(demuxer->stream);

    i = tab_pos;

//    priv->index_table_size[stream_id] = i;
//    if (priv->index_table[stream_id] == NULL)
//	priv->index_table[stream_id] = malloc(priv->index_table_size[stream_id] * sizeof(real_index_table_t));
//    else
//	priv->index_table[stream_id] = realloc(priv->index_table[stream_id],
//	    priv->index_table_size[stream_id] * sizeof(real_index_table_t));
    
    priv->index_table[stream_id][i].timestamp = timestamp;
    priv->index_table[stream_id][i].offset = stream_tell(demuxer->stream)-12;
    priv->index_table[stream_id][i].len = len;
    priv->index_table[stream_id][i].packetno = entries;
    priv->index_table[stream_id][i].flags = flags;

    tab_pos++;

    /* skip data */
    stream_skip(demuxer->stream, len-12);
    }
    dump_index(demuxer, stream_id);
    if (data_pos)
	goto read_index;

end:
    demuxer->seekable = 1; /* got index, we're able to seek */
    if (i == -256)
	stream_reset(demuxer->stream);
    stream_seek(demuxer->stream, origpos);
    if (i == -256)
	return 0;
    else
	return 1;
}

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;
    sh_audio_t *sh_audio = NULL;
    int len;
    int timestamp;
    int stream_id;
    int i;
    int flags;

loop:
    /* also don't check if no num_of_packets was defined in header */
    if ((priv->current_packet > priv->num_of_packets) &&
	(priv->num_of_packets != -10))
	return 0; /* EOF */
    stream_skip(demuxer->stream, 2); /* version */
    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;
    }
    stream_id = stream_read_word(demuxer->stream);
    timestamp = stream_read_dword(demuxer->stream);

    stream_skip(demuxer->stream, 1); /* reserved */
    flags = stream_read_char(demuxer->stream);
    /* flags:		*/
    /*  0x1 - reliable  */
    /* 	0x2 - keyframe	*/

//    printf("packet#%d: pos: %d, len: %d, stream_id: %d, timestamp: %d, flags: %x\n",
//	priv->current_packet, stream_tell(demuxer->stream)-12, len, stream_id, timestamp, flags);

    priv->current_packet++;
    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 */
	    sh_audio = ds->sh;
	    priv->current_apacket++;
	    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 */
	    priv->current_vpacket++;
	    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);
#if 0
    ds_read_packet(ds, demuxer->stream, len, timestamp/90000.0f,
	demuxer->filepos, (flags & 0x2) ? 0x10 : 0);
#else
    {
	demux_packet_t *dp = new_demux_packet(len);
	
	stream_read(demuxer->stream, dp->buffer, len);
	/* if DNET, swap bytes! */
	if (sh_audio != NULL)
	    if (sh_audio->format == 0x2000)
	    {
		char *ptr = dp->buffer;

		for (i = 0; i < len; i += 2)
		{
		    const char tmp = ptr[0];
		    ptr[0] = ptr[1];
		    ptr[1] = tmp;
		    ptr += 2;
		}
	    }
	dp->pts = timestamp/90000.0f;
	dp->pos = demuxer->filepos;
	dp->flags = (flags & 0x2) ? 0x10 : 0;
	ds_add_packet(ds, dp);
    }
#endif

    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); /* version */
//    stream_skip(demuxer->stream, 4);
    i = stream_read_dword(demuxer->stream);
    printf("File version: %d\n", i);
    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_id, chunk_pos, chunk_size;
	
	chunk_pos = stream_tell(demuxer->stream);
	chunk_id = stream_read_dword_le(demuxer->stream);
	chunk_size = stream_read_dword(demuxer->stream);

	stream_skip(demuxer->stream, 2); /* version */
	
	if (chunk_size < 10)
	    goto fail;
	
	printf("Chunk: %.4s (%x) (size: 0x%x, offset: 0x%x)\n",
	    (char *)&chunk_id, chunk_id, chunk_size, chunk_pos);
	
	switch(chunk_id)
	{
	    case MKTAG('P', 'R', 'O', 'P'):
		/* Properties header */

		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 */
		priv->index_chunk_offset = stream_read_dword(demuxer->stream);
		printf("First index chunk offset: 0x%x\n", priv->index_chunk_offset);
		priv->data_chunk_offset = stream_read_dword(demuxer->stream)+10;
		printf("First data chunk offset: 0x%x\n", priv->data_chunk_offset);
		stream_skip(demuxer->stream, 2); /* nb streams */
#if 0
		stream_skip(demuxer->stream, 2); /* flags */
#else
		{
		    int flags = stream_read_word(demuxer->stream);
		    
		    if (flags)
		    {
		    printf("Flags (%x): ", flags);
		    if (flags & 0x1)
			printf("[save allowed] ");
		    if (flags & 0x2)
			printf("[perfect play (more buffers)] ");
		    if (flags & 0x4)
			printf("[live broadcast] ");
		    printf("\n");
		    }
		}
#endif
		break;
	    case MKTAG('C', 'O', 'N', 'T'):
	    {
		/* Content description header */
		char *buf;
		int len;

		len = stream_read_word(demuxer->stream);
		if (len > 0)
		{
		    buf = malloc(len+1);
		    stream_read(demuxer->stream, buf, len);
		    buf[len] = 0;
		    demux_info_add(demuxer, "name", buf);
		    free(buf);
		}

		len = stream_read_word(demuxer->stream);
		if (len > 0)
		{
		    buf = malloc(len+1);
		    stream_read(demuxer->stream, buf, len);
		    buf[len] = 0;
		    demux_info_add(demuxer, "author", buf);
		    free(buf);
		}

		len = stream_read_word(demuxer->stream);
		if (len > 0)
		{
		    buf = malloc(len+1);
		    stream_read(demuxer->stream, buf, len);
		    buf[len] = 0;
		    demux_info_add(demuxer, "copyright", buf);
		    free(buf);
		}

		len = stream_read_word(demuxer->stream);
		if (len > 0)
		{
		    buf = malloc(len+1);
	    	    stream_read(demuxer->stream, buf, len);
		    buf[len] = 0;
		    demux_info_add(demuxer, "comment", buf);
		    free(buf);
		}
		break;
	    }
	    case MKTAG('M', 'D', 'P', 'R'):
	    {
		/* Media properties header */
		int stream_id;
		int bitrate;
		int codec_data_size;
		int codec_pos;
		int tmp;

		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); /* avg 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 (name) */
		skip_str(1, demuxer);	/* mimetype */
		
		/* Type specific header */
		codec_data_size = stream_read_dword(demuxer->stream);
		codec_pos = stream_tell(demuxer->stream);

		tmp = stream_read_dword(demuxer->stream);

		if (tmp == MKTAG(0xfd, 'a', 'r', '.'))
		{
		    /* audio header */
		    sh_audio_t *sh = new_sh_audio(demuxer, stream_id);
		    char buf[128]; /* for codec name */
		    int frame_size;
		    int version;

		    printf("Found audio stream!\n");
		    version = stream_read_word(demuxer->stream);
		    printf("version: %d\n", version);
//		    stream_skip(demuxer->stream, 2); /* version (4 or 5) */
		    stream_skip(demuxer->stream, 2);
		    stream_skip(demuxer->stream, 4); /* .ra4 or .ra5 */
		    stream_skip(demuxer->stream, 4);
		    stream_skip(demuxer->stream, 2); /* version (4 or 5) */
		    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 */
		    frame_size = stream_read_word(demuxer->stream);
		    printf("frame_size: %d\n", frame_size);
		    stream_skip(demuxer->stream, 4);
		    
		    if (version == 5)
			stream_skip(demuxer->stream, 6);

		    sh->samplerate = stream_read_word(demuxer->stream);
		    stream_skip(demuxer->stream, 4);
		    sh->channels = stream_read_word(demuxer->stream);
		    printf("samplerate: %d, channels: %d\n",
			sh->samplerate, sh->channels);

		    if (version == 5)
		    {
			stream_skip(demuxer->stream, 4);
			stream_read(demuxer->stream, buf, 4);
			buf[4] = 0;
		    }
		    else
		    {		
			/* Desc #1 */
			skip_str(1, demuxer);
			/* Desc #2 */
			get_str(1, demuxer, buf, sizeof(buf));
		    }

		    /* Emulate WAVEFORMATEX struct: */
		    sh->wf = malloc(sizeof(WAVEFORMATEX));
		    memset(sh->wf, 0, sizeof(WAVEFORMATEX));
		    sh->wf->nChannels = sh->channels;
		    sh->wf->wBitsPerSample = 16;
		    sh->wf->nSamplesPerSec = sh->samplerate;
		    sh->wf->nAvgBytesPerSec = bitrate;
		    sh->wf->nBlockAlign = frame_size;
		    sh->wf->cbSize = 0;

		    tmp = 1; /* supported audio codec */
		    switch (MKTAG(buf[0], buf[1], buf[2], buf[3]))
		    {
			case MKTAG('d', 'n', 'e', 't'):
			    printf("Audio: DNET -> AC3\n");
			    sh->format = 0x2000;
			    break;
			case MKTAG('s', 'i', 'p', 'r'):
			    printf("Audio: SiproLab's ACELP.net\n");
			    sh->format = 0x130;
			    /* for buggy directshow loader */
			    sh->wf = realloc(sh->wf, 18+4);
			    sh->wf->wBitsPerSample = 0;
			    sh->wf->nAvgBytesPerSec = 1055;
			    sh->wf->nBlockAlign = 19;
//			    sh->wf->nBlockAlign = frame_size / 288;
			    sh->wf->cbSize = 4;
			    buf[0] = 30;
			    buf[1] = 1;
			    buf[2] = 1;
			    buf[3] = 0;
			    memcpy((sh->wf+18), (char *)&buf[0], 4);
//			    sh->wf[sizeof(WAVEFORMATEX)+1] = 30;
//			    sh->wf[sizeof(WAVEFORMATEX)+2] = 1;
//			    sh->wf[sizeof(WAVEFORMATEX)+3] = 1;
//			    sh->wf[sizeof(WAVEFORMATEX)+4] = 0;
			    break;
			case MKTAG('c', 'o', 'o', 'k'):
			    printf("Audio: Real's GeneralCooker (?) (RealAudio G2?) (unsupported)\n");
			    tmp = 0;
			    break;
			case MKTAG('a', 't', 'r', 'c'):
			    printf("Audio: Sony ATRAC3 (RealAudio 8?) (unsupported)\n");
			    sh->format = 0x270;

			    sh->wf->nAvgBytesPerSec = 8268;
			    sh->wf->nBlockAlign = 192;
			    break;
			default:
			    printf("Audio: Unknown (%s)\n", buf);
			    tmp = 0;
			    sh->format = MKTAG(buf[0], buf[1], buf[2], buf[3]);
		    }

		    sh->wf->wFormatTag = sh->format;
		    
		    print_wave_header(sh->wf);

		    if (tmp)
		    {
			/* 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
			free(sh->wf);
//		    break;
		}
		else
//		case MKTAG('V', 'I', 'D', 'O'):
		{
		    /* video header */
		    sh_video_t *sh = new_sh_video(demuxer, stream_id);

		    tmp = stream_read_dword_le(demuxer->stream);
		    printf("video: %.4s (%x)\n", (char *)&tmp, tmp);
		    if (tmp != MKTAG('V', 'I', 'D', 'O'))
		    {
			mp_msg(MSGT_DEMUX, MSGL_ERR, "Not audio/video stream or unsupported!\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 */
		    tmp = stream_read_dword(demuxer->stream);
		    printf("H.263 ID: %x\n", tmp);
		    switch (tmp)
		    {
			case 0x10000000:
			    /* sub id: 0 */
			    /* codec id: rv10 */
			    break;
			case 0x10003000:
			case 0x10003001:
			    /* sub id: 3 */
			    /* codec id: rv10 */
			    sh->bih->biCompression = sh->format = mmioFOURCC('R', 'V', '1', '3');
			    break;
			case 0x20001000:
			case 0x20100001:
			    /* codec id: rv20 */
			    break;
			default:
			    /* codec id: none */
			    printf("unknown id: %x\n", tmp);
		    }
		        
		    /* 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++;
		    }
		}
//		break;
//	    default:
skip_this_chunk:
		/* skip codec info */
		tmp = stream_tell(demuxer->stream) - codec_pos;
		stream_skip(demuxer->stream, codec_data_size - tmp);
		break;
//	    }
	    }
	    case MKTAG('D', 'A', 'T', 'A'):
		goto header_end;
	    case MKTAG('I', 'N', 'D', 'X'):
	    default:
		printf("Unknown chunk: %x\n", chunk_id);
		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);

    if (priv->num_of_packets == 0)
	priv->num_of_packets = -10;

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

    if (index_mode == 2)
	generate_index(demuxer);
    else if (priv->index_chunk_offset && ((index_mode == 1) || (index_mode == 2)))
	parse_index_chunk(demuxer);

fail:
    return;
}

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

    return;
}

#if 1
/* XXX: FIXME!!!! */
/* will complete it later - please upload RV10 samples WITH INDEX CHUNK */
int demux_seek_real(demuxer_t *demuxer, float rel_seek_secs, int flags)
{
    real_priv_t *priv = demuxer->priv;
    demux_stream_t *d_audio = demuxer->audio;
    demux_stream_t *d_video = demuxer->video;
    sh_audio_t *sh_audio = d_audio->sh;
    sh_video_t *sh_video = d_video->sh;
    int rel_seek_frames = sh_video->fps*rel_seek_secs;
    int video_chunk_pos = d_video->pos;
    int vid = priv->current_vid, aid = priv->current_aid;
    int i;

    printf("real seek\n\n");

    if ((index_mode != 1) && (index_mode != 2))
	return 0;

    if (flags & 1)
	/* seek absolute */
	priv->current_apacket = priv->current_vpacket = 0;

    if (flags & 2)
	rel_seek_frames = rel_seek_secs*sh_video->fps;

    printf("rel_seek_frames: %d\n", rel_seek_frames);
    
    priv->current_apacket+=rel_seek_frames;
    priv->current_vpacket+=rel_seek_frames;

    if ((priv->current_apacket > priv->index_table_size[vid]) ||
	(priv->current_vpacket > priv->index_table_size[aid]))
	return 0;

    if (priv->current_apacket > priv->current_vpacket)
    {
	while (!(priv->index_table[vid][priv->current_vpacket].flags & 0x2))
	    priv->current_vpacket++;
	i = priv->index_table[vid][priv->current_vpacket].offset;
    }
    else
    {
	while (!(priv->index_table[aid][priv->current_apacket].flags & 0x2))
	    priv->current_apacket++;	
	i = priv->index_table[aid][priv->current_apacket].offset;
    }
    
    printf("seek: pos: %d, packets: a: %d, v: %d\n",
	i, priv->current_apacket, priv->current_vpacket);
    stream_seek(demuxer->stream, i);
}
#endif