transcode.c

uclinux 下的vlc播放器源代码

        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 */
        for( i = 0; i < id->i_filter; i++ )
        {
            p_audio_block =
                id->pp_filter[i]->pf_audio_filter( id->pp_filter[i],
                                                   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;

        p_block = id->p_encoder->pf_encode_audio( id->p_encoder, p_audio_buf );
        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 );
    if( p_buffer ) 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) );
    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 )
{
    if( p_buffer && p_buffer->p_sys ) block_Release( p_buffer->p_sys );
    if( p_buffer ) free( p_buffer );
}

/*
 * video
 */
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 = 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) );
    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;
    /* id->p_decoder->p_cfg = p_sys->p_video_cfg; */

    id->p_decoder->p_module =
        module_Need( id->p_decoder, "decoder", "$codec", 0 );

    if( !id->p_decoder->p_module )
    {
        msg_Err( p_stream, "cannot find decoder" );
        return VLC_EGENERIC;
    }

    /*
     * Open encoder.
     * Because some info about the decoded input will only be available
     * once the first frame is decoded, we actually only test the availability
     * of the encoder here.
     */

    /* 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.video.i_chroma = id->p_decoder->fmt_out.i_codec;

    /* The dimensions will be set properly later on.
     * Just put sensible values so we can test an encoder is available. */
    id->p_encoder->fmt_in.video.i_width =
        id->p_encoder->fmt_out.video.i_width ?
        id->p_encoder->fmt_out.video.i_width :
        id->p_decoder->fmt_in.video.i_width ?
        id->p_decoder->fmt_in.video.i_width : 16;
    id->p_encoder->fmt_in.video.i_height =
        id->p_encoder->fmt_out.video.i_height ?
        id->p_encoder->fmt_out.video.i_height :
        id->p_decoder->fmt_in.video.i_height ?
        id->p_decoder->fmt_in.video.i_height : 16;
    id->p_encoder->fmt_in.video.i_frame_rate = 25;
    id->p_encoder->fmt_in.video.i_frame_rate_base = 1;

    id->p_encoder->i_threads = p_sys->i_threads;
    id->p_encoder->p_cfg = p_sys->p_video_cfg;

    id->p_encoder->p_module =
        module_Need( id->p_encoder, "encoder", p_sys->psz_venc, VLC_TRUE );
    if( !id->p_encoder->p_module )
    {
        msg_Err( p_stream, "cannot find encoder (%s)", p_sys->psz_venc );
        module_Unneed( id->p_decoder, id->p_decoder->p_module );
        id->p_decoder->p_module = 0;
        return VLC_EGENERIC;
    }

    /* Close the encoder.
     * We'll open it only when we have the first frame. */
    module_Unneed( id->p_encoder, id->p_encoder->p_module );
    if( id->p_encoder->fmt_out.p_extra )
        free( id->p_encoder->fmt_out.p_extra );
    id->p_encoder->p_module = NULL;

    if( p_sys->i_threads >= 1 )
    {
        int i_priority = p_sys->b_high_priority ? VLC_THREAD_PRIORITY_OUTPUT :
                           VLC_THREAD_PRIORITY_VIDEO;
        p_sys->id_video = id;
        vlc_mutex_init( p_stream, &p_sys->lock_out );
        vlc_cond_init( p_stream, &p_sys->cond );
        memset( p_sys->pp_pics, 0, sizeof(p_sys->pp_pics) );
        p_sys->i_first_pic = 0;
        p_sys->i_last_pic = 0;
        p_sys->p_buffers = NULL;
        p_sys->b_die = p_sys->b_error = 0;
        if( vlc_thread_create( p_sys, "encoder", EncoderThread, i_priority,
                               VLC_FALSE ) )
        {
            msg_Err( p_stream, "cannot spawn encoder thread" );
            module_Unneed( id->p_decoder, id->p_decoder->p_module );
            id->p_decoder->p_module = 0;
            return VLC_EGENERIC;
        }
    }

    return VLC_SUCCESS;
}

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

     /* Calculate scaling, padding, cropping etc. */

     /* width/height of source */
     int i_src_width = id->p_decoder->fmt_out.video.i_width;
     int i_src_height = id->p_decoder->fmt_out.video.i_height;

     /* with/height scaling */
     float f_scale_width = 1;
     float f_scale_height = 1;

     /* width/height of output stream */
     int i_dst_width;
     int i_dst_height;

     /* aspect ratio */
     float f_aspect = (float)id->p_decoder->fmt_out.video.i_aspect /
                             VOUT_ASPECT_FACTOR;

     msg_Dbg( p_stream, "decoder aspect is %i:%i",
                  id->p_decoder->fmt_out.video.i_aspect, VOUT_ASPECT_FACTOR );

     /* Change f_aspect from source frame to source pixel */
     f_aspect = f_aspect * i_src_height / i_src_width;
     msg_Dbg( p_stream, "source pixel aspect is %f:1", f_aspect );

     /* width/height after cropping */
     p_sys->i_src_x_offset = p_sys->i_crop_left & ~1;
     p_sys->i_src_y_offset = p_sys->i_crop_top & ~1;
     p_sys->i_crop_width = i_src_width - ( p_sys->i_crop_left & ~1 ) -
                            ( p_sys->i_crop_right & ~1 );
     p_sys->i_crop_height = i_src_height - ( p_sys->i_crop_top & ~1 ) -
                            ( p_sys->i_crop_bottom & ~1 );

    /* Calculate scaling factor for specified parameters */
    if( id->p_encoder->fmt_out.video.i_width <= 0 &&
        id->p_encoder->fmt_out.video.i_height <= 0 && p_sys->f_scale )
    {
        /* Global scaling. Make sure width will remain a factor of 16 */
        float f_real_scale;
        int  i_new_height;
        int i_new_width = i_src_width * p_sys->f_scale;

        if( i_new_width % 16 <= 7 && i_new_width >= 16 )
            i_new_width -= i_new_width % 16;
        else
            i_new_width += 16 - i_new_width % 16;

        f_real_scale = (float)( i_new_width ) / (float) i_src_width;

        i_new_height = __MAX( 16, i_src_height * (float)f_real_scale );

        f_scale_width = f_real_scale;
        f_scale_height = (float) i_new_height / (float) i_src_height;
    }
    else if( id->p_encoder->fmt_out.video.i_width > 0 &&
             id->p_encoder->fmt_out.video.i_height <= 0 )
    {
        /* Only width specified */
        f_scale_width = (float)id->p_encoder->fmt_out.video.i_width /
                             p_sys->i_crop_width;
        f_scale_height = f_scale_width;
    }
    else if( id->p_encoder->fmt_out.video.i_width <= 0 &&
             id->p_encoder->fmt_out.video.i_height > 0 )
    {
         /* Only height specified */
         f_scale_height = (float)id->p_encoder->fmt_out.video.i_height /
                              p_sys->i_crop_height;
         f_scale_width = f_scale_height;
     }
     else if( id->p_encoder->fmt_out.video.i_width > 0 &&
              id->p_encoder->fmt_out.video.i_height > 0 )
     {
         /* Width and height specified */
         f_scale_width = (float)id->p_encoder->fmt_out.video.i_width
                               / p_sys->i_crop_width;
         f_scale_height = (float)id->p_encoder->fmt_out.video.i_height
                               / p_sys->i_crop_height;
     }

     /* check maxwidth and maxheight */
     /* note: maxwidth and maxheight currently does not handle
      * canvas and padding, just scaling and cropping. */

     if( p_sys->i_maxwidth && f_scale_width > (float)p_sys->i_maxwidth /
                                                     p_sys->i_crop_width )
     {
         f_scale_width = (float)p_sys->i_maxwidth / p_sys->i_crop_width;
     }
     if( p_sys->i_maxheight && f_scale_height > (float)p_sys->i_maxheight /
                                                       p_sys->i_crop_height )
     {
         f_scale_height = (float)p_sys->i_maxheight / p_sys->i_crop_height;
     }

     /* Change aspect ratio from source pixel to scaled pixel */
     f_aspect = f_aspect * f_scale_height / f_scale_width;
     msg_Dbg( p_stream, "scaled pixel aspect is %f:1", f_aspect );

     /* Correct scaling for target aspect ratio */
     /* Shrink video if necessary */
     if ( p_sys->i_canvas_aspect > 0 )
     {
         float f_target_aspect = (float)p_sys->i_canvas_aspect /
                                        VOUT_ASPECT_FACTOR;

         if( p_sys->i_canvas_width > 0 && p_sys->i_canvas_height > 0)
         {
             /* Calculate pixel aspect of canvas */
             f_target_aspect = f_target_aspect / p_sys->i_canvas_width *
                               p_sys->i_canvas_height;
         }
         if( f_target_aspect > f_aspect )
         {
             /* Reduce width scale to increase aspect */
             f_scale_width = f_scale_width * f_aspect / f_target_aspect;
         }
         else
         {
             /* Reduce height scale to decrease aspect */
             f_scale_height = f_scale_height * f_target_aspect / f_aspect;
         }
         f_aspect = f_target_aspect;
         msg_Dbg( p_stream, "canvas scaled pixel aspect is %f:1", f_aspect );
     }

     /* f_scale_width and f_scale_height are now final */

     /* Calculate width, height from scaling */
     /* Make sure its multiple of 2 */

     i_dst_width = 2 * (int)( p_sys->i_crop_width * f_scale_width / 2 + 0.5 );
     i_dst_height = 2 *
                    (int)( p_sys->i_crop_height * f_scale_height / 2 + 0.5 );

     p_sys->i_nopadd_width = i_dst_width;
     p_sys->i_nopadd_height = i_dst_height;
     p_sys->i_dst_x_offset = 0;
     p_sys->i_dst_y_offset = 0;

     /* Handle canvas and padding */

     if( p_sys->i_canvas_width <= 0 )
     {
         /* No canvas width set, add explicit padding border */
         i_dst_width = p_sys->i_nopadd_width + ( p_sys->i_padd_left & ~1 ) +
                      ( p_sys->i_padd_right & ~1 );
         p_sys->i_dst_x_offset = ( p_sys->i_padd_left & ~1 );
     }
     else
     {
         /* Canvas set, check if we have to padd or crop */

         if( p_sys->i_canvas_width < p_sys->i_nopadd_width )
         {
             /* need to crop more, but keep same scaling */
             int i_crop = 2 * (int)( ( p_sys->i_canvas_width & ~1 ) /
                                       f_scale_width / 2 + 0.5 );

             p_sys->i_src_x_offset += ( ( p_sys->i_crop_width - i_crop ) / 2 )
                                           & ~1;
             p_sys->i_crop_width = i_crop;
             i_dst_width = p_sys->i_canvas_width & ~1;
             p_sys->i_nopadd_width = i_dst_width;
         }
         else if( p_sys->i_canvas_width > p_sys->i_nopadd_width )
         {
             /* need to padd */
             i_dst_width = p_sys->i_canvas_width & ~1;
             p_sys->i_dst_x_offset = ( i_dst_width - p_sys->i_nopadd_width )/2;
             p_sys->i_dst_x_offset = p_sys->i_dst_x_offset & ~1;
         }