Add resume support to AAC files.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10720 a1c6a512-1295-4272-9138-f99709370657

apps/codecs/aac.c

@@ -75,9 +75,11 @@ next_track:
         goto exit;
     }
 
-    while (!rb->taginfo_ready)
-        rb->yield();
+    while (!*ci->taginfo_ready && !ci->stop_codec)
+        ci->sleep(1);
   
+    samplesdone = ci->id3->offset;
+
     ci->configure(DSP_SET_FREQUENCY, (long *)(rb->id3->frequency));
 
     stream_create(&input_stream,ci);
@@ -117,7 +119,17 @@ next_track:
     ci->id3->frequency=s;
 
     i=0;
-    samplesdone=0;
+    
+    if (samplesdone > 0) {
+        if (alac_seek_raw(&demux_res, &input_stream, samplesdone,
+                          &samplesdone, (int *)&i)) {
+            elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
+            ci->set_elapsed(elapsedtime);
+        } else {
+            samplesdone=0;
+        }
+    }
+
     /* The main decoding loop */
     while (i < demux_res.num_sample_byte_sizes) {
         rb->yield();

apps/codecs/libm4a/m4a.c

@@ -230,3 +230,64 @@ unsigned int alac_seek (demux_res_t* demux_res,
     return 0;
   }
 }
+
+/* Seek to file_loc (or close to it).  Return 1 on success (and
+   modify samplesdone and currentblock), 0 if failed 
+
+   Seeking uses the following array:
+
+     the sample_byte_size array contains the length in bytes of
+     each block ("sample" in Applespeak).
+
+   So we just find the last block before (or at) the requested position.
+
+   Each ALAC block seems to be independent of all the others.
+ */
+
+unsigned int alac_seek_raw (demux_res_t* demux_res, 
+                        stream_t* stream,
+                        unsigned int file_loc, 
+                        uint32_t* samplesdone, int* currentblock)
+{
+  unsigned int i;
+  unsigned int j;
+  unsigned int newblock;
+  unsigned int newsample;
+  unsigned int newpos;
+
+  /* First check we have the appropriate metadata - we should always
+     have it. */
+  if ((demux_res->num_time_to_samples==0) ||
+    (demux_res->num_sample_byte_sizes==0)) { return 0; }
+
+  /* Find the destination block from the sample_byte_size array. */
+  newpos=demux_res->mdat_offset;
+  for (i=0;(i<demux_res->num_sample_byte_sizes) &&
+           (newpos+demux_res->sample_byte_size[i]<=file_loc);i++) {
+    newpos+=demux_res->sample_byte_size[i];
+  }
+  
+  newblock=i;
+  newsample=0;
+
+  /* Get the sample offset of the block */
+  for (i=0,j=0;(i<demux_res->num_time_to_samples) && (j<newblock);
+       i++,j+=demux_res->time_to_sample[i].sample_count) {
+    if (newblock-j < demux_res->time_to_sample[i].sample_count) {
+        newsample+=(newblock-j)*demux_res->time_to_sample[i].sample_duration;
+        break;
+    } else {
+        newsample+=(demux_res->time_to_sample[i].sample_duration
+                   * demux_res->time_to_sample[i].sample_count);
+    }
+  }
+
+  /* We know the new file position, so let's try to seek to it */
+  if (stream->ci->seek_buffer(newpos)) {
+    *samplesdone=newsample;
+    *currentblock=newblock;
+    return 1;
+  } else {
+    return 0;
+  }
+}

apps/codecs/libm4a/m4a.h

@@ -100,5 +100,9 @@ unsigned int alac_seek (demux_res_t* demux_res,
                         stream_t* stream,
                         unsigned int sample_loc, 
                         uint32_t* samplesdone, int* currentblock);
+unsigned int alac_seek_raw (demux_res_t* demux_res, 
+                        stream_t* stream,
+                        unsigned int file_loc, 
+                        uint32_t* samplesdone, int* currentblock);
 
 #endif /* STREAM_H */