libhb/decavcodec.c

   1 /* $Id: decavcodec.c,v 1.6 2005/03/06 04:08:54 titer Exp $
   2
   3    This file is part of the HandBrake source code.
   4    Homepage: <http://handbrake.m0k.org/>.
   5    It may be used under the terms of the GNU General Public License. */
   6
   7 #include "hb.h"
   8
   9 #include "ffmpeg/avcodec.h"
  10
  11 int  decavcodecInit( hb_work_object_t *, hb_job_t * );
  12 int  decavcodecWork( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
  13 void decavcodecClose( hb_work_object_t * );
  14
  15 hb_work_object_t hb_decavcodec =
  16 {
  17     WORK_DECAVCODEC,
  18     "MPGA decoder (libavcodec)",
  19     decavcodecInit,
  20     decavcodecWork,
  21     decavcodecClose
  22 };
  23
  24 struct hb_work_private_s
  25 {
  26     hb_job_t       * job;
  27
  28     AVCodecContext * context;
  29     int64_t          pts_last;
  30     AVCodecParserContext *parser;
  31 };
  32
  33
  34 /***********************************************************************
  35  * hb_work_decavcodec_init
  36  ***********************************************************************
  37  *
  38  **********************************************************************/
  39 int decavcodecInit( hb_work_object_t * w, hb_job_t * job )
  40 {
  41     AVCodec * codec;
  42
  43     hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
  44     w->private_data = pv;
  45
  46     pv->job   = job;
  47
  48     codec = avcodec_find_decoder( CODEC_ID_MP2 );
  49     pv->parser = av_parser_init(CODEC_ID_MP2);
  50
  51     pv->context = avcodec_alloc_context();
  52     avcodec_open( pv->context, codec );
  53     pv->pts_last = -1;
  54
  55     return 0;
  56 }
  57
  58 /***********************************************************************
  59  * Close
  60  ***********************************************************************
  61  *
  62  **********************************************************************/
  63 void decavcodecClose( hb_work_object_t * w )
  64 {
  65     hb_work_private_t * pv = w->private_data;
  66     av_parser_close(pv->parser);
  67     avcodec_close( pv->context );
  68 }
  69
  70 /***********************************************************************
  71  * Work
  72  ***********************************************************************
  73  *
  74  **********************************************************************/
  75 int decavcodecWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
  76                     hb_buffer_t ** buf_out )
  77 {
  78     hb_work_private_t * pv = w->private_data;
  79     hb_buffer_t * in = *buf_in, * buf, * last = NULL;
  80     int   pos, len, out_size, i, uncompressed_len;
  81     short buffer[AVCODEC_MAX_AUDIO_FRAME_SIZE];
  82     uint64_t cur;
  83     unsigned char *parser_output_buffer;
  84     int parser_output_buffer_len;
  85
  86     *buf_out = NULL;
  87
  88     if( in->start < 0 ||
  89         ( pv->pts_last > 0 &&
  90           in->start > pv->pts_last &&
  91           in->start - pv->pts_last < 5000 ) ) /* Hacky */
  92     {
  93         cur = pv->pts_last;
  94     }
  95     else
  96     {
  97         cur = in->start;
  98     }
  99
 100     pos = 0;
 101     while( pos < in->size )
 102     {
 103         len = av_parser_parse(pv->parser, pv->context,&parser_output_buffer,&parser_output_buffer_len,in->data + pos,in->size - pos,cur,cur);
 104
 105         out_size = 0;
 106         uncompressed_len = 0;
 107         if (parser_output_buffer_len)
 108           uncompressed_len = avcodec_decode_audio( pv->context, buffer, &out_size,
 109                                     parser_output_buffer, parser_output_buffer_len );
 110         if( out_size )
 111         {
 112             short * s16;
 113             float * fl32;
 114
 115             buf = hb_buffer_init( 2 * out_size );
 116
 117             int sample_size_in_bytes = 2;   // Default to 2 bytes
 118             switch (pv->context->sample_fmt)
 119             {
 120               case SAMPLE_FMT_S16:
 121                 sample_size_in_bytes = 2;
 122                 break;
 123               /* We should handle other formats here - but that needs additional format conversion work below */
 124               /* For now we'll just report the error and try to carry on */
 125               default:
 126                 hb_log("decavcodecWork - Unknown Sample Format from avcodec_decode_audio (%d) !", pv->context->sample_fmt);
 127                 break;
 128             }
 129
 130             buf->start = cur;
 131             buf->stop  = cur + 90000 * ( out_size / (sample_size_in_bytes * pv->context->channels) ) /
 132                          pv->context->sample_rate;
 133             cur = buf->stop;
 134
 135             s16  = buffer;
 136             fl32 = (float *) buf->data;
 137             for( i = 0; i < out_size / 2; i++ )
 138             {
 139                 fl32[i] = s16[i];
 140             }
 141
 142             if( last )
 143             {
 144                 last = last->next = buf;
 145             }
 146             else
 147             {
 148                 *buf_out = last = buf;
 149             }
 150         }
 151
 152         pos += len;
 153     }
 154
 155     pv->pts_last = cur;
 156
 157     return HB_WORK_OK;
 158 }
 159