scaletempo.c

VLC Player Source Code

 *****************************************************************************/
static size_t calculate_output_buffer_size( aout_filter_t   *p_filter,
                                            size_t           bytes_in )
{
    aout_filter_sys_t *p = p_filter->p_sys;
    size_t bytes_out = 0;
    int bytes_to_out = bytes_in + p->bytes_queued - p->bytes_to_slide;
    if( bytes_to_out >= (int)p->bytes_queue_max ) {
      /* while (total_buffered - stride_length * n >= queue_max) n++ */
      bytes_out = p->bytes_stride * ( (unsigned)(
          ( bytes_to_out - p->bytes_queue_max + /* rounding protection */ p->bytes_per_frame )
          / p->bytes_stride_scaled ) + 1 );
    }
    return bytes_out;
}

/*****************************************************************************
 * reinit_buffers: reinitializes buffers in p_filter->p_sys
 *****************************************************************************/
static int reinit_buffers( aout_filter_t *p_filter )
{
    aout_filter_sys_t *p = p_filter->p_sys;
    unsigned i,j;

    unsigned frames_stride = p->ms_stride * p->sample_rate / 1000.0;
    p->bytes_stride = frames_stride * p->bytes_per_frame;

    /* overlap */
    unsigned frames_overlap = frames_stride * p->percent_overlap;
    if( frames_overlap < 1 )
    { /* if no overlap */
        p->bytes_overlap    = 0;
        p->bytes_standing   = p->bytes_stride;
        p->samples_standing = p->bytes_standing / p->bytes_per_sample;
        p->output_overlap   = NULL;
    }
    else
    {
        unsigned prev_overlap   = p->bytes_overlap;
        p->bytes_overlap    = frames_overlap * p->bytes_per_frame;
        p->samples_overlap  = frames_overlap * p->samples_per_frame;
        p->bytes_standing   = p->bytes_stride - p->bytes_overlap;
        p->samples_standing = p->bytes_standing / p->bytes_per_sample;
        p->buf_overlap      = malloc( p->bytes_overlap );
        p->table_blend      = malloc( p->samples_overlap * 4 ); /* sizeof (int32|float) */
        if( !p->buf_overlap || !p->table_blend )
            return VLC_ENOMEM;
        if( p->bytes_overlap > prev_overlap )
            memset( (uint8_t *)p->buf_overlap + prev_overlap, 0, p->bytes_overlap - prev_overlap );

        float *pb = p->table_blend;
        float t = (float)frames_overlap;
        for( i = 0; i<frames_overlap; i++ )
        {
            float v = i / t;
            for( j = 0; j < p->samples_per_frame; j++ )
                *pb++ = v;
        }
        p->output_overlap = output_overlap_float;
    }

    /* best overlap */
    p->frames_search = ( frames_overlap <= 1 ) ? 0 : p->ms_search * p->sample_rate / 1000.0;
    if( p->frames_search < 1 )
    { /* if no search */
        p->best_overlap_offset = NULL;
    }
    else
    {
        unsigned bytes_pre_corr = ( p->samples_overlap - p->samples_per_frame ) * 4; /* sizeof (int32|float) */
        p->buf_pre_corr = malloc( bytes_pre_corr );
        p->table_window = malloc( bytes_pre_corr );
        if( ! p->buf_pre_corr || ! p->table_window )
            return VLC_ENOMEM;
        float *pw = p->table_window;
        for( i = 1; i<frames_overlap; i++ )
        {
            float v = i * ( frames_overlap - i );
            for( j = 0; j < p->samples_per_frame; j++ )
                *pw++ = v;
        }
        p->best_overlap_offset = best_overlap_offset_float;
    }

    unsigned new_size = ( p->frames_search + frames_stride + frames_overlap ) * p->bytes_per_frame;
    if( p->bytes_queued > new_size )
    {
        if( p->bytes_to_slide > p->bytes_queued )
        {
          p->bytes_to_slide -= p->bytes_queued;
          p->bytes_queued    = 0;
        }
        else
        {
            unsigned new_queued = __MIN( p->bytes_queued - p->bytes_to_slide, new_size );
            memmove( p->buf_queue,
                     p->buf_queue + p->bytes_queued - new_queued,
                     new_queued );
            p->bytes_to_slide = 0;
            p->bytes_queued   = new_queued;
        }
    }
    p->bytes_queue_max = new_size;
    p->buf_queue = malloc( p->bytes_queue_max );
    if( ! p->buf_queue )
        return VLC_ENOMEM;

    p->bytes_stride_scaled  = p->bytes_stride * p->scale;
    p->frames_stride_scaled = p->bytes_stride_scaled / p->bytes_per_frame;

    msg_Dbg( VLC_OBJECT(p_filter),
             "%.3f scale, %.3f stride_in, %i stride_out, %i standing, %i overlap, %i search, %i queue, %s mode",
             p->scale,
             p->frames_stride_scaled,
             (int)( p->bytes_stride / p->bytes_per_frame ),
             (int)( p->bytes_standing / p->bytes_per_frame ),
             (int)( p->bytes_overlap / p->bytes_per_frame ),
             p->frames_search,
             (int)( p->bytes_queue_max / p->bytes_per_frame ),
             "fl32");

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Open: initialize as "audio filter"
 *****************************************************************************/
static int Open( vlc_object_t *p_this )
{
    aout_filter_t     *p_filter = (aout_filter_t *)p_this;
    aout_filter_sys_t *p_sys;
    bool b_fit = true;

    if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2' ) ||
        p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
    {
        b_fit = false;
        p_filter->input.i_format = p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
        msg_Warn( p_filter, "bad input or output format" );
    }
    if( ! AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
    {
        b_fit = false;
        memcpy( &p_filter->output, &p_filter->input, sizeof(audio_sample_format_t) );
        msg_Warn( p_filter, "input and output formats are not similar" );
    }

    if( ! b_fit )
        return VLC_EGENERIC;

    p_filter->pf_do_work = DoWork;
    p_filter->b_in_place = false;

    /* Allocate structure */
    p_sys = p_filter->p_sys = malloc( sizeof(aout_filter_sys_t) );
    if( ! p_sys )
        return VLC_ENOMEM;

    p_sys->scale             = 1.0;
    p_sys->sample_rate       = p_filter->input.i_rate;
    p_sys->samples_per_frame = aout_FormatNbChannels( &p_filter->input );
    p_sys->bytes_per_sample  = 4;
    p_sys->bytes_per_frame   = p_sys->samples_per_frame * p_sys->bytes_per_sample;

    msg_Dbg( p_this, "format: %5i rate, %i nch, %i bps, %s",
             p_sys->sample_rate,
             p_sys->samples_per_frame,
             p_sys->bytes_per_sample,
             "fl32" );

    p_sys->ms_stride       = config_GetInt(   p_this, "scaletempo-stride" );
    p_sys->percent_overlap = config_GetFloat( p_this, "scaletempo-overlap" );
    p_sys->ms_search       = config_GetInt(   p_this, "scaletempo-search" );

    msg_Dbg( p_this, "params: %i stride, %.3f overlap, %i search",
             p_sys->ms_stride, p_sys->percent_overlap, p_sys->ms_search );

    p_sys->i_buf = 0;
    p_sys->p_buffers[0] = NULL;
    p_sys->p_buffers[1] = NULL;

    p_sys->buf_queue      = NULL;
    p_sys->buf_overlap    = NULL;
    p_sys->table_blend    = NULL;
    p_sys->buf_pre_corr   = NULL;
    p_sys->table_window   = NULL;
    p_sys->bytes_overlap  = 0;
    p_sys->bytes_queued   = 0;
    p_sys->bytes_to_slide = 0;
    p_sys->frames_stride_error = 0;

    if( reinit_buffers( p_filter ) != VLC_SUCCESS )
    {
        Close( p_this );
        return VLC_EGENERIC;
    }
    return VLC_SUCCESS;
}

static void Close( vlc_object_t *p_this )
{
    aout_filter_t *p_filter = (aout_filter_t *)p_this;
    aout_filter_sys_t *p_sys = p_filter->p_sys;
    free( p_sys->buf_queue );
    free( p_sys->buf_overlap );
    free( p_sys->table_blend );
    free( p_sys->buf_pre_corr );
    free( p_sys->table_window );
    free( p_sys->p_buffers[0] );
    free( p_sys->p_buffers[1] );
    free( p_filter->p_sys );
}

/*****************************************************************************
 * DoWork: aout_filter wrapper for transform_buffer
 *****************************************************************************/
static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
                    aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
{
    VLC_UNUSED(p_aout);
    aout_filter_sys_t *p = p_filter->p_sys;

    if( p_filter->input.i_rate == p->sample_rate ) {
      memcpy( p_out_buf->p_buffer, p_in_buf->p_buffer, p_in_buf->i_nb_bytes );
      p_out_buf->i_nb_bytes   = p_in_buf->i_nb_bytes;
      p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
      return;
    }

    double scale = p_filter->input.i_rate / (double)p->sample_rate;
    if( scale != p->scale ) {
      p->scale = scale;
      p->bytes_stride_scaled  = p->bytes_stride * p->scale;
      p->frames_stride_scaled = p->bytes_stride_scaled / p->bytes_per_frame;
      p->bytes_to_slide = 0;
      msg_Dbg( p_filter, "%.3f scale, %.3f stride_in, %i stride_out",
               p->scale,
               p->frames_stride_scaled,
               (int)( p->bytes_stride / p->bytes_per_frame ) );
    }

    size_t i_outsize = calculate_output_buffer_size ( p_filter, p_in_buf->i_nb_bytes );
    if( i_outsize > p_out_buf->i_size ) {
        void *temp = realloc( p->p_buffers[ p->i_buf ], i_outsize );
        if( temp == NULL )
        {
            return;
        }
        p->p_buffers[ p->i_buf ] = temp;
        p_out_buf->p_buffer = p->p_buffers[ p->i_buf ];
        p->i_buf = ! p->i_buf;
    }

    size_t bytes_out = transform_buffer( p_filter,
        p_in_buf->p_buffer, p_in_buf->i_nb_bytes,
        p_out_buf->p_buffer );

    p_out_buf->i_nb_bytes   = bytes_out;
    p_out_buf->i_nb_samples = bytes_out / p->bytes_per_frame;
}