Commit first part of FS#10832 by Juliusz Chroboczek. Allows playback of unstreamable AAC/ALAC files by stepping through the file to find the index, potientially rebuffering. This is likely to impose a battery life hit on files which are unstreamable and not much smaller then the buffer, but should not impact streamable files at all.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24147 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 18 insertions, 10 deletions

diff --git a/apps/codecs/libm4a/demux.c b/apps/codecs/libm4a/demux.c
index 00fd313..9f887b6 100644
--- a/apps/codecs/libm4a/demux.c
+++ b/apps/codecs/libm4a/demux.c
@@ -746,7 +746,10 @@ int qtmovie_read(stream_t *file, demux_res_t *demux_res)
         chunk_len = stream_read_uint32(qtmovie.stream);
         if (stream_eof(qtmovie.stream))
         {
-            return 0;
+            if(qtmovie.res->mdat_offset == 0 || qtmovie.res->format == 0)
+                return 0;
+            stream_seek(qtmovie.stream, qtmovie.res->mdat_offset);
+            return 1;
         }
 
         if (chunk_len == 1)
@@ -767,20 +770,19 @@ int qtmovie_read(stream_t *file, demux_res_t *demux_res)
                return 0;
             }
             break;
-            /* once we hit mdat we stop reading and return.
-             * this is on the assumption that there is no furhter interesting
-             * stuff in the stream. if there is stuff will fail (:()).
-             * But we need the read pointer to be at the mdat stuff
-             * for the decoder. And we don't want to rely on fseek/ftell,
-             * as they may not always be avilable */
         case MAKEFOURCC('m','d','a','t'):
             read_chunk_mdat(&qtmovie, chunk_len);
             /* Keep track of start of stream in file - used for seeking */
             qtmovie.res->mdat_offset=stream_tell(qtmovie.stream);
             /* There can be empty mdats before the real one. If so, skip them */
-            if (qtmovie.res->mdat_len > 0) {
+            if (qtmovie.res->mdat_len == 0)
+                break;
+            /* If we've already seen the format, assume there's nothing
+               interesting after the mdat chunk (the file is "streamable").
+               This avoids having to seek, which might cause rebuffering. */
+            if(qtmovie.res->format > 0)
                 return 1;
-            }
+            stream_skip(qtmovie.stream, chunk_len - 8);
             break;
 
             /*  these following atoms can be skipped !!!! */
diff --git a/apps/codecs/libm4a/m4a.c b/apps/codecs/libm4a/m4a.c
index 92e619d..42295e7 100644
--- a/apps/codecs/libm4a/m4a.c
+++ b/apps/codecs/libm4a/m4a.c
@@ -103,7 +103,12 @@ uint8_t stream_read_uint8(stream_t *stream)
 
 void stream_skip(stream_t *stream, size_t skip)
 {
-  stream->ci->advance_buffer(skip);
+    stream->ci->advance_buffer(skip);
+}
+
+void stream_seek(stream_t *stream, size_t offset)
+{
+    stream->ci->seek_buffer(offset);
 }
 
 int stream_eof(stream_t *stream)
diff --git a/apps/codecs/libm4a/m4a.h b/apps/codecs/libm4a/m4a.h
index e2d4376..066f54b 100644
--- a/apps/codecs/libm4a/m4a.h
+++ b/apps/codecs/libm4a/m4a.h
@@ -113,6 +113,7 @@ int8_t stream_read_int8(stream_t *stream);
 uint8_t stream_read_uint8(stream_t *stream);
 
 void stream_skip(stream_t *stream, size_t skip);
+void stream_seek(stream_t *stream, size_t offset);
 
 int stream_eof(stream_t *stream);