ogg.c

uclinux 下的vlc播放器源代码

 *****************************************************************************
 * The initial page of a logical stream is marked as a 'bos' page.
 * Furthermore, the Ogg specification mandates that grouped bitstreams begin
 * together and all of the initial pages must appear before any data pages.
 *
 * On success this function returns VLC_SUCCESS.
 ****************************************************************************/
static int Ogg_FindLogicalStreams( demux_t *p_demux )
{
    demux_sys_t *p_ogg = p_demux->p_sys  ;
    ogg_packet oggpacket;
    ogg_page oggpage;
    int i_stream;

#define p_stream p_ogg->pp_stream[p_ogg->i_streams - 1]

    while( Ogg_ReadPage( p_demux, &oggpage ) == VLC_SUCCESS )
    {
        if( ogg_page_bos( &oggpage ) )
        {

            /* All is wonderful in our fine fine little world.
             * We found the beginning of our first logical stream. */
            while( ogg_page_bos( &oggpage ) )
            {
                p_ogg->i_streams++;
                p_ogg->pp_stream =
                    realloc( p_ogg->pp_stream, p_ogg->i_streams *
                             sizeof(logical_stream_t *) );

                p_stream = malloc( sizeof(logical_stream_t) );
                memset( p_stream, 0, sizeof(logical_stream_t) );
                p_stream->p_headers = 0;
                p_stream->secondary_header_packets = 0;

                es_format_Init( &p_stream->fmt, 0, 0 );

                /* Setup the logical stream */
                p_stream->i_serial_no = ogg_page_serialno( &oggpage );
                ogg_stream_init( &p_stream->os, p_stream->i_serial_no );

                /* Extract the initial header from the first page and verify
                 * the codec type of tis Ogg bitstream */
                if( ogg_stream_pagein( &p_stream->os, &oggpage ) < 0 )
                {
                    /* error. stream version mismatch perhaps */
                    msg_Err( p_demux, "error reading first page of "
                             "Ogg bitstream data" );
                    return VLC_EGENERIC;
                }

                /* FIXME: check return value */
                ogg_stream_packetpeek( &p_stream->os, &oggpacket );

                /* Check for Vorbis header */
                if( oggpacket.bytes >= 7 &&
                    ! memcmp( &oggpacket.packet[1], "vorbis", 6 ) )
                {
                    Ogg_ReadVorbisHeader( p_stream, &oggpacket );
                    msg_Dbg( p_demux, "found vorbis header" );
                }
                /* Check for Speex header */
                else if( oggpacket.bytes >= 7 &&
                    ! memcmp( &oggpacket.packet[0], "Speex", 5 ) )
                {
                    Ogg_ReadSpeexHeader( p_stream, &oggpacket );
                    msg_Dbg( p_demux, "found speex header, channels: %i, "
                             "rate: %i,  bitrate: %i",
                             p_stream->fmt.audio.i_channels,
                             (int)p_stream->f_rate, p_stream->fmt.i_bitrate );
                }
                /* Check for Flac header (< version 1.1.1) */
                else if( oggpacket.bytes >= 4 &&
                    ! memcmp( &oggpacket.packet[0], "fLaC", 4 ) )
                {
                    msg_Dbg( p_demux, "found FLAC header" );

                    /* Grrrr!!!! Did they really have to put all the
                     * important info in the second header packet!!!
                     * (STREAMINFO metadata is in the following packet) */
                    p_stream->b_force_backup = 1;

                    p_stream->fmt.i_cat = AUDIO_ES;
                    p_stream->fmt.i_codec = VLC_FOURCC( 'f','l','a','c' );
                }
                /* Check for Flac header (>= version 1.1.1) */
                else if( oggpacket.bytes >= 13 && oggpacket.packet[0] ==0x7F &&
                    ! memcmp( &oggpacket.packet[1], "FLAC", 4 ) &&
                    ! memcmp( &oggpacket.packet[9], "fLaC", 4 ) )
                {
                    int i_packets = ((int)oggpacket.packet[7]) << 8 |
                        oggpacket.packet[8];
                    msg_Dbg( p_demux, "found FLAC header version %i.%i "
                             "(%i header packets)",
                             oggpacket.packet[5], oggpacket.packet[6],
                             i_packets );

                    p_stream->b_force_backup = 1;

                    p_stream->fmt.i_cat = AUDIO_ES;
                    p_stream->fmt.i_codec = VLC_FOURCC( 'f','l','a','c' );
                    oggpacket.packet += 13; oggpacket.bytes -= 13;
                    Ogg_ReadFlacHeader( p_demux, p_stream, &oggpacket );
                }
                /* Check for Theora header */
                else if( oggpacket.bytes >= 7 &&
                         ! memcmp( &oggpacket.packet[1], "theora", 6 ) )
                {
                    Ogg_ReadTheoraHeader( p_stream, &oggpacket );

                    msg_Dbg( p_demux,
                             "found theora header, bitrate: %i, rate: %f",
                             p_stream->fmt.i_bitrate, p_stream->f_rate );
                }
                /* Check for Tarkin header */
                else if( oggpacket.bytes >= 7 &&
                         ! memcmp( &oggpacket.packet[1], "tarkin", 6 ) )
                {
                    oggpack_buffer opb;

                    msg_Dbg( p_demux, "found tarkin header" );
                    p_stream->fmt.i_cat = VIDEO_ES;
                    p_stream->fmt.i_codec = VLC_FOURCC( 't','a','r','k' );

                    /* Cheat and get additionnal info ;) */
                    oggpack_readinit( &opb, oggpacket.packet, oggpacket.bytes);
                    oggpack_adv( &opb, 88 );
                    oggpack_adv( &opb, 104 );
                    p_stream->fmt.i_bitrate = oggpack_read( &opb, 32 );
                    p_stream->f_rate = 2; /* FIXME */
                    msg_Dbg( p_demux,
                             "found tarkin header, bitrate: %i, rate: %f",
                             p_stream->fmt.i_bitrate, p_stream->f_rate );
                }
                /* Check for Annodex header */
                else if( oggpacket.bytes >= 7 &&
                         ! memcmp( &oggpacket.packet[0], "Annodex", 7 ) )
                {
                    Ogg_ReadAnnodexHeader( VLC_OBJECT(p_demux), p_stream,
                                           &oggpacket );
                    /* kill annodex track */
                    free( p_stream );
                    p_ogg->i_streams--;
                }
                /* Check for Annodex header */
                else if( oggpacket.bytes >= 7 &&
                         ! memcmp( &oggpacket.packet[0], "AnxData", 7 ) )
                {
                    Ogg_ReadAnnodexHeader( VLC_OBJECT(p_demux), p_stream,
                                           &oggpacket );
                }
                else if( oggpacket.bytes >= 142 &&
                         !memcmp( &oggpacket.packet[1],
                                   "Direct Show Samples embedded in Ogg", 35 ))
                {
                    /* Old header type */

                    /* Check for video header (old format) */
                    if( GetDWLE((oggpacket.packet+96)) == 0x05589f80 &&
                        oggpacket.bytes >= 184 )
                    {
                        p_stream->fmt.i_cat = VIDEO_ES;
                        p_stream->fmt.i_codec =
                            VLC_FOURCC( oggpacket.packet[68],
                                        oggpacket.packet[69],
                                        oggpacket.packet[70],
                                        oggpacket.packet[71] );
                        msg_Dbg( p_demux, "found video header of type: %.4s",
                                 (char *)&p_stream->fmt.i_codec );

                        p_stream->fmt.video.i_frame_rate = 10000000;
                        p_stream->fmt.video.i_frame_rate_base =
                            GetQWLE((oggpacket.packet+164));
                        p_stream->f_rate = 10000000.0 /
                            GetQWLE((oggpacket.packet+164));
                        p_stream->fmt.video.i_bits_per_pixel =
                            GetWLE((oggpacket.packet+182));
                        if( !p_stream->fmt.video.i_bits_per_pixel )
                            /* hack, FIXME */
                            p_stream->fmt.video.i_bits_per_pixel = 24;
                        p_stream->fmt.video.i_width =
                            GetDWLE((oggpacket.packet+176));
                        p_stream->fmt.video.i_height =
                            GetDWLE((oggpacket.packet+180));

                        msg_Dbg( p_demux,
                                 "fps: %f, width:%i; height:%i, bitcount:%i",
                                 p_stream->f_rate,
                                 p_stream->fmt.video.i_width,
                                 p_stream->fmt.video.i_height,
                                 p_stream->fmt.video.i_bits_per_pixel);

                    }
                    /* Check for audio header (old format) */
                    else if( GetDWLE((oggpacket.packet+96)) == 0x05589F81 )
                    {
                        unsigned int i_extra_size;
                        unsigned int i_format_tag;

                        p_stream->fmt.i_cat = AUDIO_ES;

                        i_extra_size = GetWLE((oggpacket.packet+140));
                        if( i_extra_size )
                        {
                            p_stream->fmt.i_extra = i_extra_size;
                            p_stream->fmt.p_extra = malloc( i_extra_size );
                            memcpy( p_stream->fmt.p_extra,
                                    oggpacket.packet + 142, i_extra_size );
                        }

                        i_format_tag = GetWLE((oggpacket.packet+124));
                        p_stream->fmt.audio.i_channels =
                            GetWLE((oggpacket.packet+126));
                        p_stream->f_rate = p_stream->fmt.audio.i_rate =
                            GetDWLE((oggpacket.packet+128));
                        p_stream->fmt.i_bitrate =
                            GetDWLE((oggpacket.packet+132)) * 8;
                        p_stream->fmt.audio.i_blockalign =
                            GetWLE((oggpacket.packet+136));
                        p_stream->fmt.audio.i_bitspersample =
                            GetWLE((oggpacket.packet+138));

                        wf_tag_to_fourcc( i_format_tag,
                                          &p_stream->fmt.i_codec, 0 );

                        if( p_stream->fmt.i_codec ==
                            VLC_FOURCC('u','n','d','f') )
                        {
                            p_stream->fmt.i_codec = VLC_FOURCC( 'm', 's',
                                ( i_format_tag >> 8 ) & 0xff,
                                i_format_tag & 0xff );
                        }

                        msg_Dbg( p_demux, "found audio header of type: %.4s",
                                 (char *)&p_stream->fmt.i_codec );
                        msg_Dbg( p_demux, "audio:0x%4.4x channels:%d %dHz "
                                 "%dbits/sample %dkb/s",
                                 i_format_tag,
                                 p_stream->fmt.audio.i_channels,
                                 p_stream->fmt.audio.i_rate,
                                 p_stream->fmt.audio.i_bitspersample,
                                 p_stream->fmt.i_bitrate / 1024 );

                    }
                    else
                    {
                        msg_Dbg( p_demux, "stream %d has an old header "
                            "but is of an unknown type", p_ogg->i_streams-1 );
                        free( p_stream );
                        p_ogg->i_streams--;
                    }
                }
                else if( (*oggpacket.packet & PACKET_TYPE_BITS )
                         == PACKET_TYPE_HEADER &&
                         oggpacket.bytes >= (int)sizeof(stream_header)+1 )
                {
                    stream_header *st = (stream_header *)(oggpacket.packet+1);

                    /* Check for video header (new format) */
                    if( !strncmp( st->streamtype, "video", 5 ) )
                    {
                        p_stream->fmt.i_cat = VIDEO_ES;

                        /* We need to get rid of the header packet */
                        ogg_stream_packetout( &p_stream->os, &oggpacket );

                        p_stream->fmt.i_codec =
                            VLC_FOURCC( st->subtype[0], st->subtype[1],
                                        st->subtype[2], st->subtype[3] );
                        msg_Dbg( p_demux, "found video header of type: %.4s",
                                 (char *)&p_stream->fmt.i_codec );

                        p_stream->fmt.video.i_frame_rate = 10000000;
                        p_stream->fmt.video.i_frame_rate_base =
                            GetQWLE(&st->time_unit);
                        p_stream->f_rate = 10000000.0 /
                            GetQWLE(&st->time_unit);
                        p_stream->fmt.video.i_bits_per_pixel =
                            GetWLE(&st->bits_per_sample);
                        p_stream->fmt.video.i_width =
                            GetDWLE(&st->sh.video.width);
                        p_stream->fmt.video.i_height =
                            GetDWLE(&st->sh.video.height);

                        msg_Dbg( p_demux,
                                 "fps: %f, width:%i; height:%i, bitcount:%i",
                                 p_stream->f_rate,
                                 p_stream->fmt.video.i_width,
                                 p_stream->fmt.video.i_height,
                                 p_stream->fmt.video.i_bits_per_pixel );
                    }
                    /* Check for audio header (new format) */
                    else if( !strncmp( st->streamtype, "audio", 5 ) )
                    {
                        char p_buffer[5];
                        int i_format_tag;

                        p_stream->fmt.i_cat = AUDIO_ES;

                        /* We need to get rid of the header packet */
                        ogg_stream_packetout( &p_stream->os, &oggpacket );

                        p_stream->fmt.i_extra = GetQWLE(&st->size) -
                            sizeof(stream_header);
                        if( p_stream->fmt.i_extra )
                        {
                            p_stream->fmt.p_extra =
                                malloc( p_stream->fmt.i_extra );
                            memcpy( p_stream->fmt.p_extra, st + 1,
                                    p_stream->fmt.i_extra );
                        }

                        memcpy( p_buffer, st->subtype, 4 );
                        p_buffer[4] = '\0';
                        i_format_tag = strtol(p_buffer,NULL,16);
                        p_stream->fmt.audio.i_channels =
                            GetWLE(&st->sh.audio.channels);
                        p_stream->f_rate = p_stream->fmt.audio.i_rate =
                            GetQWLE(&st->samples_per_unit);
                        p_stream->fmt.i_bitrate =
                            GetDWLE(&st->sh.audio.avgbytespersec) * 8;
                        p_stream->fmt.audio.i_blockalign =
                            GetWLE(&st->sh.audio.blockalign);
                        p_stream->fmt.audio.i_bitspersample =
                            GetWLE(&st->bits_per_sample);

                        wf_tag_to_fourcc( i_format_tag,
                                          &p_stream->fmt.i_codec, 0 );

                        if( p_stream->fmt.i_codec ==
                            VLC_FOURCC('u','n','d','f') )
                        {
                            p_stream->fmt.i_codec = VLC_FOURCC( 'm', 's',
                                ( i_format_tag >> 8 ) & 0xff,
                                i_format_tag & 0xff );
                        }

                        msg_Dbg( p_demux, "found audio header of type: %.4s",
                                 (char *)&p_stream->fmt.i_codec );
                        msg_Dbg( p_demux, "audio:0x%4.4x channels:%d %dHz "
                                 "%dbits/sample %dkb/s",
                                 i_format_tag,
                                 p_stream->fmt.audio.i_channels,
                                 p_stream->fmt.audio.i_rate,
                                 p_stream->fmt.audio.i_bitspersample,
                                 p_stream->fmt.i_bitrate / 1024 );
                    }
                    /* Check for text (subtitles) header */
                    else if( !strncmp(st->streamtype, "text", 4) )
                    {
                        /* We need to get rid of the header packet */
                        ogg_stream_packetout( &p_stream->os, &oggpacket );

                        msg_Dbg( p_demux, "found text subtitles header" );
                        p_stream->fmt.i_cat = SPU_ES;
                        p_stream->fmt.i_codec = VLC_FOURCC('s','u','b','t');
                        p_stream->f_rate = 1000; /* granulepos is in milisec */
                    }