mp4.c

uclinux 下的vlc播放器源代码

    p_stream                = malloc( sizeof( mp4_stream_t ) );
    es_format_Copy( &p_stream->fmt, p_input->p_fmt );
    p_stream->i_track_id    = p_sys->i_nb_streams + 1;
    p_stream->i_length_neg  = 0;
    p_stream->i_entry_count = 0;
    p_stream->i_entry_max   = 1000;
    p_stream->entry         =
        calloc( p_stream->i_entry_max, sizeof( mp4_entry_t ) );
    p_stream->i_dts_start   = 0;
    p_stream->i_duration    = 0;
    p_stream->avc.i_profile = 77;
    p_stream->avc.i_profile_compat = 64;
    p_stream->avc.i_level   = 30;
    p_stream->avc.i_sps     = 0;
    p_stream->avc.sps       = NULL;
    p_stream->avc.i_pps     = 0;
    p_stream->avc.pps       = NULL;

    p_input->p_sys          = p_stream;

    msg_Dbg( p_mux, "adding input" );

    TAB_APPEND( p_sys->i_nb_streams, p_sys->pp_streams, p_stream );
    return VLC_SUCCESS;
}

/*****************************************************************************
 * DelStream:
 *****************************************************************************/
static int DelStream( sout_mux_t *p_mux, sout_input_t *p_input )
{
    msg_Dbg( p_mux, "removing input" );
    return VLC_SUCCESS;
}

static int MuxGetStream( sout_mux_t *p_mux, int *pi_stream, mtime_t *pi_dts )
{
    mtime_t i_dts;
    int     i_stream;
    int     i;

    for( i = 0, i_dts = 0, i_stream = -1; i < p_mux->i_nb_inputs; i++ )
    {
        block_fifo_t   *p_fifo = p_mux->pp_inputs[i]->p_fifo;
        block_t *p_buf;

        if( p_fifo->i_depth <= 1 )
        {
            if( p_mux->pp_inputs[i]->p_fmt->i_cat != SPU_ES )
            {
                return -1; // wait that all fifo have at least 2 packets
            }
            /* For SPU, we wait only 1 packet */
            continue;
        }

        p_buf = block_FifoShow( p_fifo );
        if( i_stream < 0 || p_buf->i_dts < i_dts )
        {
            i_dts = p_buf->i_dts;
            i_stream = i;
        }
    }
    if( pi_stream )
    {
        *pi_stream = i_stream;
    }
    if( pi_dts )
    {
        *pi_dts = i_dts;
    }
    return i_stream;
}

/*****************************************************************************
 * Mux:
 *****************************************************************************/
static int Mux( sout_mux_t *p_mux )
{
    sout_mux_sys_t *p_sys = p_mux->p_sys;

    for( ;; )
    {
        sout_input_t    *p_input;
        int             i_stream;
        mp4_stream_t    *p_stream;
        block_t         *p_data;
        mtime_t         i_dts;

        if( MuxGetStream( p_mux, &i_stream, &i_dts) < 0 )
        {
            return( VLC_SUCCESS );
        }

        p_input  = p_mux->pp_inputs[i_stream];
        p_stream = (mp4_stream_t*)p_input->p_sys;

        p_data  = block_FifoGet( p_input->p_fifo );
        if( p_stream->fmt.i_codec == VLC_FOURCC( 'h', '2', '6', '4' ) )
        {
            ConvertAVC1( p_mux, p_stream, p_data );
        }
        else if( p_stream->fmt.i_codec == VLC_FOURCC( 's', 'u', 'b', 't' ) )
        {
            p_data = ConvertSUBT( p_mux, p_stream, p_data );
        }

        if( p_stream->fmt.i_cat != SPU_ES )
        {
            /* Fix length of the sample */
            if( p_input->p_fifo->i_depth > 0 )
            {
                block_t *p_next = block_FifoShow( p_input->p_fifo );
                int64_t       i_diff  = p_next->i_dts - p_data->i_dts;

                if( i_diff < I64C(1000000 ) )   /* protection */
                {
                    p_data->i_length = i_diff;
                }
            }
            if( p_data->i_length <= 0 )
            {
                msg_Warn( p_mux, "i_length <= 0" );
                p_stream->i_length_neg += p_data->i_length - 1;
                p_data->i_length = 1;
            }
            else if( p_stream->i_length_neg < 0 )
            {
                int64_t i_recover = __MIN( p_data->i_length / 4, - p_stream->i_length_neg );

                p_data->i_length -= i_recover;
                p_stream->i_length_neg += i_recover;
            }
        }

        /* Save starting time */
        if( p_stream->i_entry_count == 0 )
        {
            p_stream->i_dts_start = p_data->i_dts;

            /* Update global dts_start */
            if( p_sys->i_dts_start <= 0 ||
                p_stream->i_dts_start < p_sys->i_dts_start )
            {
                p_sys->i_dts_start = p_stream->i_dts_start;
            }
        }

        if( p_stream->fmt.i_cat == SPU_ES && p_stream->i_entry_count > 0 )
        {
            int64_t i_length = p_data->i_dts - p_stream->i_last_dts;

            if( i_length <= 0 )
            {
                /* FIXME handle this broken case */
                i_length = 1;
            }

            /* Fix last entry */
            if( p_stream->entry[p_stream->i_entry_count-1].i_length <= 0 )
            {
                p_stream->entry[p_stream->i_entry_count-1].i_length = i_length;
            }
        }


        /* add index entry */
        p_stream->entry[p_stream->i_entry_count].i_pos    = p_sys->i_pos;
        p_stream->entry[p_stream->i_entry_count].i_size   = p_data->i_buffer;
        p_stream->entry[p_stream->i_entry_count].i_pts_dts=
            __MAX( p_data->i_pts - p_data->i_dts, 0 );
        p_stream->entry[p_stream->i_entry_count].i_length = p_data->i_length;
        p_stream->entry[p_stream->i_entry_count].i_flags  = p_data->i_flags;

        p_stream->i_entry_count++;
        /* XXX: -1 to always have 2 entry for easy adding of empty SPU */
        if( p_stream->i_entry_count >= p_stream->i_entry_max - 1 )
        {
            p_stream->i_entry_max += 1000;
            p_stream->entry =
                realloc( p_stream->entry,
                         p_stream->i_entry_max * sizeof( mp4_entry_t ) );
        }

        /* update */
        p_stream->i_duration += p_data->i_length;
        p_sys->i_pos += p_data->i_buffer;

        /* Save the DTS */
        p_stream->i_last_dts = p_data->i_dts;

        /* write data */
        sout_AccessOutWrite( p_mux->p_access, p_data );

        if( p_stream->fmt.i_cat == SPU_ES )
        {
            int64_t i_length = p_stream->entry[p_stream->i_entry_count-1].i_length;

            if( i_length != 0 )
            {
                /* TODO */
                msg_Dbg( p_mux, "writing an empty sub" ) ;

                /* Append a idx entry */
                p_stream->entry[p_stream->i_entry_count].i_pos    = p_sys->i_pos;
                p_stream->entry[p_stream->i_entry_count].i_size   = 3;
                p_stream->entry[p_stream->i_entry_count].i_pts_dts= 0;
                p_stream->entry[p_stream->i_entry_count].i_length = 0;
                p_stream->entry[p_stream->i_entry_count].i_flags  = 0;

                /* XXX: No need to grow the entry here */
                p_stream->i_entry_count++;

                /* Fix last dts */
                p_stream->i_last_dts += i_length;

                /* Write a " " */
                p_data = block_New( p_mux, 3 );
                p_data->p_buffer[0] = 0;
                p_data->p_buffer[1] = 1;
                p_data->p_buffer[2] = ' ';

                p_sys->i_pos += p_data->i_buffer;

                sout_AccessOutWrite( p_mux->p_access, p_data );
            }

            /* Fix duration */
            p_stream->i_duration = p_stream->i_last_dts - p_stream->i_dts_start;
        }
    }

    return( VLC_SUCCESS );
}

/*****************************************************************************
 *
 *****************************************************************************/
static block_t *ConvertSUBT( sout_mux_t *p_mux, mp4_stream_t *tk, block_t *p_block )
{
    p_block = block_Realloc( p_block, 2, p_block->i_buffer );

    /* No trailling '\0' */
    if( p_block->i_buffer > 2 && p_block->p_buffer[p_block->i_buffer-1] == '\0' )
        p_block->i_buffer--;

    p_block->p_buffer[0] = ( (p_block->i_buffer - 2) >> 8 )&0xff;
    p_block->p_buffer[1] = ( (p_block->i_buffer - 2)      )&0xff;

    return p_block;
}

static void ConvertAVC1( sout_mux_t *p_mux, mp4_stream_t *tk, block_t *p_block )
{
    uint8_t *last = p_block->p_buffer;  /* Assume it starts with 0x00000001 */
    uint8_t *dat  = &p_block->p_buffer[4];
    uint8_t *end = &p_block->p_buffer[p_block->i_buffer];


    /* Replace the 4 bytes start code with 4 bytes size,
     * FIXME are all startcodes 4 bytes ? (I don't think :( */
    while( dat < end )
    {
        int i_size;

        while( dat < end - 4 )
        {
            if( dat[0] == 0x00 && dat[1] == 0x00  &&
                dat[2] == 0x00 && dat[3] == 0x01 )
            {
                break;
            }
            dat++;
        }
        if( dat >= end - 4 )
        {
            dat = end;
        }

        /* Fix size */
        i_size = dat - &last[4];
        last[0] = ( i_size >> 24 )&0xff;
        last[1] = ( i_size >> 16 )&0xff;
        last[2] = ( i_size >>  8 )&0xff;
        last[3] = ( i_size       )&0xff;

        if( (last[4]&0x1f) == 7 && tk->avc.i_sps <= 0 )  /* SPS */
        {
            tk->avc.i_sps = i_size;
            tk->avc.sps = malloc( i_size );
            memcpy( tk->avc.sps, &last[4], i_size );

            tk->avc.i_profile = tk->avc.sps[1];
            tk->avc.i_profile = tk->avc.sps[2];
            tk->avc.i_level   = tk->avc.sps[3];
        }
        else if( (last[4]&0x1f) == 8 && tk->avc.i_pps <= 0 )   /* PPS */
        {
            tk->avc.i_pps = i_size;
            tk->avc.pps = malloc( i_size );
            memcpy( tk->avc.pps, &last[4], i_size );
        }

        last = dat;

        dat += 4;
    }
}


static int GetDescrLength( int i_size )
{
    if( i_size < 0x00000080 )
        return 2 + i_size;
    else if( i_size < 0x00004000 )
        return 3 + i_size;
    else if( i_size < 0x00200000 )
        return 4 + i_size;
    else
        return 5 + i_size;
}

static bo_t *GetESDS( mp4_stream_t *p_stream )
{
    bo_t *esds;
    int  i_stream_type;
    int  i_object_type_indication;
    int  i_decoder_specific_info_size;
    unsigned int i;
    int64_t i_bitrate_avg = 0;
    int64_t i_bitrate_max = 0;

    /* Compute avg/max bitrate */
    for( i = 0; i < p_stream->i_entry_count; i++ )
    {
        i_bitrate_avg += p_stream->entry[i].i_size;
        if( p_stream->entry[i].i_length > 0)
        {
            int64_t i_bitrate = I64C(8000000) * p_stream->entry[i].i_size / p_stream->entry[i].i_length;
            if( i_bitrate > i_bitrate_max )
                i_bitrate_max = i_bitrate;
        }
    }

    if( p_stream->i_duration > 0 )
        i_bitrate_avg = I64C(8000000) * i_bitrate_avg / p_stream->i_duration;
    else
        i_bitrate_avg = 0;
    if( i_bitrate_max <= 1 )
        i_bitrate_max = 0x7fffffff;

    /* */
    if( p_stream->fmt.i_extra > 0 )
    {
        i_decoder_specific_info_size =
            GetDescrLength( p_stream->fmt.i_extra );
    }
    else
    {
        i_decoder_specific_info_size = 0;
    }

    esds = box_full_new( "esds", 0, 0 );

    /* ES_Descr */
    bo_add_descr( esds, 0x03, 3 +
                  GetDescrLength( 13 + i_decoder_specific_info_size ) +
                  GetDescrLength( 1 ) );
    bo_add_16be( esds, p_stream->i_track_id );
    bo_add_8   ( esds, 0x1f );      // flags=0|streamPriority=0x1f

    /* DecoderConfigDescr */
    bo_add_descr( esds, 0x04, 13 + i_decoder_specific_info_size );

    switch( p_stream->fmt.i_codec )
    {
        case VLC_FOURCC( 'm', 'p', '4', 'v' ):
            i_object_type_indication = 0x20;
            break;
        case VLC_FOURCC( 'm', 'p', 'g', 'v' ):
            /* FIXME MPEG-I=0x6b, MPEG-II = 0x60 -> 0x65 */
            i_object_type_indication = 0x60;
            break;
        case VLC_FOURCC( 'm', 'p', '4', 'a' ):
            /* FIXME for mpeg2-aac == 0x66->0x68 */
            i_object_type_indication = 0x40;
            break;
        case VLC_FOURCC( 'm', 'p', 'g', 'a' ):
            i_object_type_indication =
                p_stream->fmt.audio.i_rate < 32000 ? 0x69 : 0x6b;
            break;
        default:
            i_object_type_indication = 0x00;
            break;
    }
    i_stream_type = p_stream->fmt.i_cat == VIDEO_ES ? 0x04 : 0x05;

    bo_add_8   ( esds, i_object_type_indication );
    bo_add_8   ( esds, ( i_stream_type << 2 ) | 1 );
    bo_add_24be( esds, 1024 * 1024 );       // bufferSizeDB
    bo_add_32be( esds, i_bitrate_max );     // maxBitrate
    bo_add_32be( esds, i_bitrate_avg );     // avgBitrate

    if( p_stream->fmt.i_extra > 0 )
    {
        int i;

        /* DecoderSpecificInfo */
        bo_add_descr( esds, 0x05, p_stream->fmt.i_extra );

        for( i = 0; i < p_stream->fmt.i_extra; i++ )
        {
            bo_add_8( esds, ((uint8_t*)p_stream->fmt.p_extra)[i] );
        }
    }

    /* SL_Descr mandatory */
    bo_add_descr( esds, 0x06, 1 );
    bo_add_8    ( esds, 0x02 );  // sl_predefined

    box_fix( esds );

    return esds;
}

static bo_t *GetWaveTag( mp4_stream_t *p_stream )
{
    bo_t *wave;
    bo_t *box;