transcode.c

VLC Player Source Code

    if( !id->p_decoder->p_module )
    {
        msg_Err( p_stream, "cannot find audio decoder" );
        return VLC_EGENERIC;
    }
    id->p_decoder->fmt_out.audio.i_bitspersample =
        aout_BitsPerSample( id->p_decoder->fmt_out.i_codec );
    fmt_last = id->p_decoder->fmt_out;
    /* Fix AAC SBR changing number of channels and sampling rate */
    if( !(id->p_decoder->fmt_in.i_codec == VLC_FOURCC('m','p','4','a') &&
        fmt_last.audio.i_rate != id->p_encoder->fmt_in.audio.i_rate &&
        fmt_last.audio.i_channels != id->p_encoder->fmt_in.audio.i_channels) )
        fmt_last.audio.i_rate = id->p_decoder->fmt_in.audio.i_rate;

    /*
     * Open encoder
     */

    /* Initialization of encoder format structures */
    es_format_Init( &id->p_encoder->fmt_in, id->p_decoder->fmt_in.i_cat,
                    id->p_decoder->fmt_out.i_codec );
    id->p_encoder->fmt_in.audio.i_format = id->p_decoder->fmt_out.i_codec;

    id->p_encoder->fmt_in.audio.i_rate = fmt_last.audio.i_rate;//id->p_encoder->fmt_out.audio.i_rate;
    id->p_encoder->fmt_in.audio.i_physical_channels =
        id->p_encoder->fmt_out.audio.i_physical_channels;
    id->p_encoder->fmt_in.audio.i_original_channels =
        id->p_encoder->fmt_out.audio.i_original_channels;
    id->p_encoder->fmt_in.audio.i_channels =
        id->p_encoder->fmt_out.audio.i_channels;
    id->p_encoder->fmt_in.audio.i_bitspersample =
        aout_BitsPerSample( id->p_encoder->fmt_in.i_codec );

    id->p_encoder->p_cfg = p_stream->p_sys->p_audio_cfg;
    id->p_encoder->p_module =
        module_Need( id->p_encoder, "encoder", p_sys->psz_aenc, true );
    if( !id->p_encoder->p_module )
    {
        msg_Err( p_stream, "cannot find audio encoder (module:%s fourcc:%4.4s)",
                 p_sys->psz_aenc ? p_sys->psz_aenc : "any",
                 (char *)&p_sys->i_acodec );
        module_Unneed( id->p_decoder, id->p_decoder->p_module );
        id->p_decoder->p_module = NULL;
        return VLC_EGENERIC;
    }
    id->p_encoder->fmt_in.audio.i_format = id->p_encoder->fmt_in.i_codec;
    id->p_encoder->fmt_in.audio.i_bitspersample =
        aout_BitsPerSample( id->p_encoder->fmt_in.i_codec );

    /* Init filter chain */
    id->p_f_chain = filter_chain_New( p_stream, "audio filter2", true,
                    transcode_audio_filter_allocation_init, NULL, NULL );
    filter_chain_Reset( id->p_f_chain, &fmt_last, &id->p_encoder->fmt_in );

    /* Load conversion filters */
    if( fmt_last.audio.i_channels != id->p_encoder->fmt_in.audio.i_channels ||
        fmt_last.audio.i_rate != id->p_encoder->fmt_in.audio.i_rate )
    {
        /* We'll have to go through fl32 first */
        fmt_last.i_codec = fmt_last.audio.i_format = VLC_FOURCC('f','l','3','2');
        fmt_last.audio.i_bitspersample = aout_BitsPerSample( fmt_last.i_codec );
        filter_chain_AppendFilter( id->p_f_chain, NULL, NULL, NULL, &fmt_last );
        fmt_last = *filter_chain_GetFmtOut( id->p_f_chain );
    }

    for( i = 0; i < 4; i++ )
    {
        if( (fmt_last.audio.i_channels !=
            id->p_encoder->fmt_in.audio.i_channels) ||
            (fmt_last.audio.i_rate != id->p_encoder->fmt_in.audio.i_rate) ||
            (fmt_last.i_codec != id->p_encoder->fmt_in.i_codec) )
        {
            msg_Dbg( p_stream, "Looking for filter "
                     "(%4.4s->%4.4s, channels %d->%d, rate %d->%d)",
                 (char *)&fmt_last.i_codec,
                 (char *)&id->p_encoder->fmt_in.i_codec,
                 fmt_last.audio.i_channels,
                 id->p_encoder->fmt_in.audio.i_channels,
                 fmt_last.audio.i_rate,
                 id->p_encoder->fmt_in.audio.i_rate );
            filter_chain_AppendFilter( id->p_f_chain, NULL, NULL,
                                       &fmt_last, &id->p_encoder->fmt_in );
            fmt_last = *filter_chain_GetFmtOut( id->p_f_chain );
        }
        else break;
    }

    /* Final checks to see if conversions were successful */
    if( fmt_last.i_codec != id->p_encoder->fmt_in.i_codec )
    {
        msg_Err( p_stream, "no audio filter found "
                           "(%4.4s->%4.4s, channels %d->%d, rate %d->%d)",
                 (char *)&fmt_last.i_codec,
                 (char *)&id->p_encoder->fmt_in.i_codec,
                 fmt_last.audio.i_channels,
                 id->p_encoder->fmt_in.audio.i_channels,
                 fmt_last.audio.i_rate,
                 id->p_encoder->fmt_in.audio.i_rate );
        transcode_audio_close( id );
        return VLC_EGENERIC;
    }

    /* Load user specified audio filters now */
    if( p_sys->psz_af2 )
    {
        id->p_uf_chain = filter_chain_New( p_stream, "audio filter2", false,
                       transcode_audio_filter_allocation_init, NULL, NULL );
        filter_chain_Reset( id->p_uf_chain, &fmt_last, &id->p_encoder->fmt_in );
        filter_chain_AppendFromString( id->p_uf_chain, p_sys->psz_af2 );
        fmt_last = *filter_chain_GetFmtOut( id->p_uf_chain );
    }

    if( fmt_last.audio.i_channels != id->p_encoder->fmt_in.audio.i_channels )
    {
#if 1
        module_Unneed( id->p_encoder, id->p_encoder->p_module );
        id->p_encoder->p_module = NULL;

        /* This might work, but only if the encoder is restarted */
        id->p_encoder->fmt_in.audio.i_channels = fmt_last.audio.i_channels;
        id->p_encoder->fmt_out.audio.i_channels = fmt_last.audio.i_channels;

        id->p_encoder->fmt_in.audio.i_physical_channels =
            id->p_encoder->fmt_in.audio.i_original_channels =
                fmt_last.audio.i_physical_channels;
        id->p_encoder->fmt_out.audio.i_physical_channels =
            id->p_encoder->fmt_out.audio.i_original_channels =
                fmt_last.audio.i_physical_channels;

        msg_Dbg( p_stream, "number of audio channels for mixing changed, "
                 "trying to reopen the encoder for mixing %i to %i channels",
                 fmt_last.audio.i_channels,
                 id->p_encoder->fmt_in.audio.i_channels );

        /* reload encoder */
        id->p_encoder->p_cfg = p_stream->p_sys->p_audio_cfg;
        id->p_encoder->p_module =
            module_Need( id->p_encoder, "encoder", p_sys->psz_aenc, true );
        if( !id->p_encoder->p_module )
        {
            msg_Err( p_stream, "cannot find audio encoder (module:%s fourcc:%4.4s)",
                     p_sys->psz_aenc ? p_sys->psz_aenc : "any",
                     (char *)&p_sys->i_acodec );
            transcode_audio_close( id );
            return VLC_EGENERIC;
        }
        id->p_encoder->fmt_in.audio.i_format = id->p_encoder->fmt_in.i_codec;
        id->p_encoder->fmt_in.audio.i_bitspersample =
            aout_BitsPerSample( id->p_encoder->fmt_in.i_codec );
#else
        msg_Err( p_stream, "no audio filter found for mixing from"
                 " %i to %i channels", fmt_last.audio.i_channels,
                 id->p_encoder->fmt_in.audio.i_channels );

        transcode_audio_close( id );
        return VLC_EGENERIC;
#endif
    }

    if( fmt_last.audio.i_rate != id->p_encoder->fmt_in.audio.i_rate )
    {
        msg_Err( p_stream, "no audio filter found for resampling from"
                 " %iHz to %iHz", fmt_last.audio.i_rate,
                 id->p_encoder->fmt_in.audio.i_rate );
#if 0
        /* FIXME : this might work, but only if the encoder is restarted */
        id->p_encoder->fmt_in.audio.i_rate = fmt_last.audio.i_rate;
        id->p_encoder->fmt_out.audio.i_rate = fmt_last.audio.i_rate;
#else
        transcode_audio_close( id );
        return VLC_EGENERIC;
#endif
    }

    /* FIXME: Hack for mp3 transcoding support */
    if( id->p_encoder->fmt_out.i_codec == VLC_FOURCC( 'm','p','3',' ' ) )
        id->p_encoder->fmt_out.i_codec = VLC_FOURCC( 'm','p','g','a' );

    return VLC_SUCCESS;
}

static void transcode_audio_close( sout_stream_id_t *id )
{
    audio_timer_close( id->p_encoder );

    /* Close decoder */
    if( id->p_decoder->p_module )
        module_Unneed( id->p_decoder, id->p_decoder->p_module );
    id->p_decoder->p_module = NULL;

    /* Close encoder */
    if( id->p_encoder->p_module )
        module_Unneed( id->p_encoder, id->p_encoder->p_module );
    id->p_encoder->p_module = NULL;

    /* Close filters */
    if( id->p_f_chain )
        filter_chain_Delete( id->p_f_chain );
    if( id->p_uf_chain )
        filter_chain_Delete( id->p_uf_chain );
}

static int transcode_audio_process( sout_stream_t *p_stream,
                                    sout_stream_id_t *id,
                                    block_t *in, block_t **out )
{
    sout_stream_sys_t *p_sys = p_stream->p_sys;
    aout_buffer_t *p_audio_buf;
    block_t *p_block, *p_audio_block;
    *out = NULL;

    while( (p_audio_buf = id->p_decoder->pf_decode_audio( id->p_decoder,
                                                          &in )) )
    {
        sout_UpdateStatistic( p_stream->p_sout, SOUT_STATISTIC_DECODED_AUDIO, 1 );
        if( p_sys->b_master_sync )
        {
            mtime_t i_dts = date_Get( &id->interpolated_pts ) + 1;
            if ( p_audio_buf->start_date - i_dts > MASTER_SYNC_MAX_DRIFT
                  || p_audio_buf->start_date - i_dts < -MASTER_SYNC_MAX_DRIFT )
            {
                msg_Dbg( p_stream, "drift is too high, resetting master sync" );
                date_Set( &id->interpolated_pts, p_audio_buf->start_date );
                i_dts = p_audio_buf->start_date + 1;
            }
            p_sys->i_master_drift = p_audio_buf->start_date - i_dts;
            date_Increment( &id->interpolated_pts, p_audio_buf->i_nb_samples );
            p_audio_buf->start_date -= p_sys->i_master_drift;
            p_audio_buf->end_date -= p_sys->i_master_drift;
        }

        p_audio_block = p_audio_buf->p_sys;
        p_audio_block->i_buffer = p_audio_buf->i_nb_bytes;
        p_audio_block->i_dts = p_audio_block->i_pts =
            p_audio_buf->start_date;
        p_audio_block->i_length = p_audio_buf->end_date -
            p_audio_buf->start_date;
        p_audio_block->i_samples = p_audio_buf->i_nb_samples;

        /* Run filter chain */
        p_audio_block = filter_chain_AudioFilter( id->p_f_chain, p_audio_block );
        if( id->p_uf_chain )
            p_audio_block = filter_chain_AudioFilter( id->p_uf_chain, p_audio_block );
        assert( p_audio_block );

        p_audio_buf->p_buffer = p_audio_block->p_buffer;
        p_audio_buf->i_nb_bytes = p_audio_block->i_buffer;
        p_audio_buf->i_nb_samples = p_audio_block->i_samples;
        p_audio_buf->start_date = p_audio_block->i_dts;
        p_audio_buf->end_date = p_audio_block->i_dts + p_audio_block->i_length;

        audio_timer_start( id->p_encoder );
        p_block = id->p_encoder->pf_encode_audio( id->p_encoder, p_audio_buf );
        audio_timer_stop( id->p_encoder );

        block_ChainAppend( out, p_block );
        block_Release( p_audio_block );
        free( p_audio_buf );
    }

    return VLC_SUCCESS;
}

static void audio_release_buffer( aout_buffer_t *p_buffer )
{
    if( p_buffer && p_buffer->p_sys ) block_Release( p_buffer->p_sys );
    free( p_buffer );
}

static aout_buffer_t *audio_new_buffer( decoder_t *p_dec, int i_samples )
{
    aout_buffer_t *p_buffer;
    block_t *p_block;
    int i_size;

    if( p_dec->fmt_out.audio.i_bitspersample )
    {
        i_size = i_samples * p_dec->fmt_out.audio.i_bitspersample / 8 *
            p_dec->fmt_out.audio.i_channels;
    }
    else if( p_dec->fmt_out.audio.i_bytes_per_frame &&
             p_dec->fmt_out.audio.i_frame_length )
    {
        i_size = i_samples * p_dec->fmt_out.audio.i_bytes_per_frame /
            p_dec->fmt_out.audio.i_frame_length;
    }
    else
    {
        i_size = i_samples * 4 * p_dec->fmt_out.audio.i_channels;
    }

    p_buffer = malloc( sizeof(aout_buffer_t) );
    if( !p_buffer ) return NULL;
    p_buffer->b_discontinuity = false;
    p_buffer->pf_release = audio_release_buffer;
    p_buffer->p_sys = p_block = block_New( p_dec, i_size );

    p_buffer->p_buffer = p_block->p_buffer;
    p_buffer->i_size = p_buffer->i_nb_bytes = p_block->i_buffer;
    p_buffer->i_nb_samples = i_samples;
    p_block->i_samples = i_samples;

    return p_buffer;
}

static void audio_del_buffer( decoder_t *p_dec, aout_buffer_t *p_buffer )
{
    VLC_UNUSED(p_dec);
    if( p_buffer && p_buffer->p_sys ) block_Release( p_buffer->p_sys );
    free( p_buffer );
}

/*
 * video
 */

static int transcode_video_filter_allocation_init( filter_t *p_filter,
                                                   void *p_data )
{
    sout_stream_sys_t *p_sys = (sout_stream_sys_t*)p_data;
    int i;

    p_filter->pf_vout_buffer_new = video_new_buffer_filter;
    p_filter->pf_vout_buffer_del = video_del_buffer_filter;

    p_filter->p_owner = malloc( sizeof(filter_owner_sys_t) );
    if( !p_filter->p_owner )
        return VLC_EGENERIC;

    for( i = 0; i < PICTURE_RING_SIZE; i++ )
        p_filter->p_owner->pp_pics[i] = 0;
    p_filter->p_owner->p_sys = p_sys;

    return VLC_SUCCESS;
}

static void transcode_video_filter_allocation_clear( filter_t *p_filter )
{
    int j;

    /* Clean-up pictures ring buffer */
    for( j = 0; j < PICTURE_RING_SIZE; j++ )
    {
        if( p_filter->p_owner->pp_pics[j] )
            video_del_buffer( VLC_OBJECT(p_filter),
                              p_filter->p_owner->pp_pics[j] );
    }
    free( p_filter->p_owner );
}

static int transcode_video_new( sout_stream_t *p_stream, sout_stream_id_t *id )
{
    sout_stream_sys_t *p_sys = p_stream->p_sys;
    int i;

    /* Open decoder
     * Initialization of decoder structures
     */
    id->p_decoder->fmt_out = id->p_decoder->fmt_in;
    id->p_decoder->fmt_out.i_extra = 0;
    id->p_decoder->fmt_out.p_extra = 0;
    id->p_decoder->pf_decode_video = NULL;
    id->p_decoder->pf_get_cc = NULL;
    id->p_decoder->pf_get_cc = 0;
    id->p_decoder->pf_vout_buffer_new = video_new_buffer_decoder;
    id->p_decoder->pf_vout_buffer_del = video_del_buffer_decoder;
    id->p_decoder->pf_picture_link    = video_link_picture_decoder;
    id->p_decoder->pf_picture_unlink  = video_unlink_picture_decoder;
    id->p_decoder->p_owner = malloc( sizeof(decoder_owner_sys_t) );
    if( !id->p_decoder->p_owner )
        return VLC_EGENERIC;

    for( i = 0; i < PICTURE_RING_SIZE; i++ )
        id->p_decoder->p_owner->pp_pics[i] = 0;
    id->p_decoder->p_owner->p_sys = p_sys;