lav_io.c

Motion JPEG编解码器源代码

               res = scan_jpeg(jpgdata, size, n);
               if (res) { internal_error=ERROR_JPEG; return -1; }

               if(!jpeg_app0_offset) continue;

               /* APP0 marker should be at least 14+2 bytes */
               if(get_int2(jpgdata+jpeg_app0_offset+2) < 16 ) continue;

               jpgdata[jpeg_app0_offset+4] = 'A';
               jpgdata[jpeg_app0_offset+5] = 'V';
               jpgdata[jpeg_app0_offset+6] = 'I';
               jpgdata[jpeg_app0_offset+7] = '1';
               jpgdata[jpeg_app0_offset+8] = lav_file->format=='a' ? n+1 : 2-n;

               /* Update pointer and len for second field */
               jpgdata += jpeg_padded_len;
               jpglen  -= jpeg_padded_len;
            }
            break;

         case 'j':

            jpgdata = buff;
            jpglen = size;
            break;

#ifdef HAVE_LIBQUICKTIME
         case 'q':

            jpgdata = buff;
            jpglen  = size;

            /* Loop over both fields */

            for(n=0;n<2;n++)
            {
               /* Scan the entire JPEG field data - APP1 marker MUST be present */
               res = scan_jpeg(jpgdata,jpglen,0);
               if(res || !jpeg_app1_offset) { internal_error=ERROR_JPEG; return -1; }

               /* Length of APP1 marker must be at least 40 + 2 bytes */
               if ( get_int2(jpgdata+jpeg_app1_offset+2) < 42)
               { internal_error=ERROR_JPEG; return -1; }

               /* Fill in data */
               put_int4(jpgdata+jpeg_app1_offset+ 4,0);
               put_int4(jpgdata+jpeg_app1_offset+ 8,QUICKTIME_MJPG_TAG);
               put_int4(jpgdata+jpeg_app1_offset+12,jpeg_field_size);
               put_int4(jpgdata+jpeg_app1_offset+16,jpeg_padded_len);
               put_int4(jpgdata+jpeg_app1_offset+20,n==0?jpeg_padded_len:0);
               put_int4(jpgdata+jpeg_app1_offset+24,jpeg_quant_offset);
               put_int4(jpgdata+jpeg_app1_offset+28,jpeg_huffman_offset);
               put_int4(jpgdata+jpeg_app1_offset+32,jpeg_image_offset);
               put_int4(jpgdata+jpeg_app1_offset+36,jpeg_scan_offset);
               put_int4(jpgdata+jpeg_app1_offset+40,jpeg_data_offset);

               /* Update pointer and len for second field */
               jpgdata += jpeg_padded_len;
               jpglen  -= jpeg_padded_len;
            }
            break;
#endif
      }
   }
   
   res = 0; /* Silence gcc */
   for(n=0;n<count;n++)
   {
      switch(lav_file->format)
      {
         case 'a':
         case 'A':
            if(n==0)
               res = AVI_write_frame( lav_file->avi_fd, buff, size );
            else
               res = AVI_dup_frame( lav_file->avi_fd );
            break;
         case 'j':
            if (n==0)
               write(lav_file->jpeg_fd, buff, size);
            break;
#ifdef HAVE_LIBQUICKTIME
         case 'q':
            res = quicktime_write_frame( lav_file->qt_fd, buff, size, 0 );
            break;
#endif
         default:
            res = -1;
      }
      if (res) break;
   }

   return res;
}

int lav_write_audio(lav_file_t *lav_file, uint8_t *buff, long samps)
{
   int res;
#ifdef HAVE_LIBQUICKTIME
   int i, j;
   int16_t *qt_audio = (int16_t *)buff, **qt_audion;
   int channels = lav_audio_channels(lav_file);

   qt_audion = malloc(channels * sizeof (int16_t **));
   for (i = 0; i < channels; i++)
	qt_audion[i] = (int16_t *)malloc(samps * lav_file->bps);
#endif

   video_format = lav_file->format; internal_error = 0; /* for error messages */

   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         res = AVI_write_audio( lav_file->avi_fd, buff, samps*lav_file->bps);
         break;
#ifdef HAVE_LIBQUICKTIME
      case 'q':
	/* Deinterleave the audio into the two channels. */
	for (i = 0; i < samps; i++)
	    {
	    for (j = 0; j < channels; j++)
		qt_audion[j][i] = qt_audio[(2*i) + j];
	    }
	res = lqt_encode_audio_track(lav_file->qt_fd, qt_audion, NULL,samps,0);
	free(qt_audion[0]);
	free(qt_audion[1]);
	free(qt_audion);
        break;
#endif
      default:
         res = -1;
   }

   return res;
}

long lav_video_frames(lav_file_t *lav_file)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_video_frames(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_video_length(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

int lav_video_width(lav_file_t *lav_file)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_video_width(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_video_width(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

int lav_video_height(lav_file_t *lav_file)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_video_height(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_video_height(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

double lav_frame_rate(lav_file_t *lav_file)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_frame_rate(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_frame_rate(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

int lav_video_interlacing(lav_file_t *lav_file)
{
   return lav_file->interlacing;
}

void lav_video_sampleaspect(lav_file_t *lav_file, int *sar_w, int *sar_h)
{
  *sar_w = lav_file->sar_w;
  *sar_h = lav_file->sar_h;
  return;
}

int lav_video_MJPG_chroma(lav_file_t *lav_file)
{
	return lav_file->MJPG_chroma;
}

const char *lav_video_compressor(lav_file_t *lav_file)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_video_compressor(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_video_compressor(lav_file->qt_fd,0);
#endif
   }
   return "N/A";
}

int lav_audio_channels(lav_file_t *lav_file)
{
   if(!lav_file->has_audio) return 0;
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_audio_channels(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_track_channels(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

int lav_audio_bits(lav_file_t *lav_file)
{
   if(!lav_file->has_audio) return 0;
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_audio_bits(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_audio_bits(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

long lav_audio_rate(lav_file_t *lav_file)
{
   if(!lav_file->has_audio) return 0;
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_audio_rate(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_sample_rate(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

long lav_audio_samples(lav_file_t *lav_file)
{
   if(!lav_file->has_audio) return 0;
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_audio_bytes(lav_file->avi_fd)/lav_file->bps;
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_audio_length(lav_file->qt_fd,0);
#endif
   }
   return -1;
}

long lav_frame_size(lav_file_t *lav_file, long frame)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_frame_size(lav_file->avi_fd,frame);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_frame_size(lav_file->qt_fd,frame,0);
#endif
   }
   return -1;
}

int lav_seek_start(lav_file_t *lav_file)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_seek_start(lav_file->avi_fd);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_seek_start(lav_file->qt_fd);
#endif
   }
   return -1;
}

int lav_set_video_position(lav_file_t *lav_file, long frame)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_set_video_position(lav_file->avi_fd,frame);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_set_video_position(lav_file->qt_fd,frame,0);
#endif
   }
   return -1;
}

int lav_read_frame(lav_file_t *lav_file, uint8_t *vidbuf)
{
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_read_frame(lav_file->avi_fd,vidbuf);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         return quicktime_read_frame(lav_file->qt_fd,vidbuf,0);
#endif
   }
   return -1;
}

int lav_set_audio_position(lav_file_t *lav_file, long sample)
{
   if(!lav_file->has_audio) return 0;
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_set_audio_position(lav_file->avi_fd,sample*lav_file->bps);
#ifdef HAVE_LIBQUICKTIME
      case 'q':
         quicktime_set_audio_position(lav_file->qt_fd,sample,0);
#endif
   }
   return -1;
}

long lav_read_audio(lav_file_t *lav_file, uint8_t *audbuf, long samps)
{
#ifdef	HAVE_LIBQUICKTIME
   int64_t last_pos, start_pos;
   int res, i, j;
   int16_t *qt_audio = (int16_t *)audbuf, **qt_audion;
   int channels = lav_audio_channels(lav_file);

   qt_audion = malloc(channels * sizeof (int16_t **));
   for (i = 0; i < channels; i++)
	qt_audion[i] = (int16_t *)malloc(samps * lav_file->bps);
#endif

   if(!lav_file->has_audio)
   {
      internal_error = ERROR_NOAUDIO;
      return(-1);
   }
   video_format = lav_file->format; internal_error = 0; /* for error messages */
   switch(lav_file->format)
   {
      case 'a':
      case 'A':
         return AVI_read_audio(lav_file->avi_fd,audbuf,samps*lav_file->bps)/lav_file->bps;
#ifdef HAVE_LIBQUICKTIME
      case 'q':
	start_pos = quicktime_audio_position(lav_file->qt_fd, 0);
	lqt_decode_audio_track(lav_file->qt_fd, qt_audion, NULL, samps, 0);
	last_pos = lqt_last_audio_position(lav_file->qt_fd, 0);
	res = last_pos - start_pos;
	if (res <= 0)
	   goto out;
	/* Interleave the channels of audio into the one buffer provided */
	for (i =0; i < res; i++)
	    {
	    for (j = 0; j < channels; j++)
		qt_audio[(2*i) + j] = qt_audion[j][i];
	    }
out:
	 free(qt_audion[0]);
	 free(qt_audion[1]);
	 free(qt_audion);
         return(res);
#endif
   }
   return -1;
}

lav_file_t *lav_open_input_file(char *filename)
{
   int n;
   const char *video_comp = NULL;
#ifdef	HAVE_LIBQUICKTIME
   char *audio_comp;
#endif
   unsigned char *frame = NULL; /* Make sure un-init segfaults! */
   long len;
   int jpg_height, jpg_width, ncomps, hf[3], vf[3];
   int ierr;

   lav_file_t *lav_fd = (lav_file_t*) malloc(sizeof(lav_file_t));

   if(lav_fd==0) { internal_error=ERROR_MALLOC; return 0; }