Remove the mallocs for the codecdata in the m4a parser and assume a maximum size of 64 bytes (see comments in source). Also clean up the alac_set_info() function a little and make it alignment-safe. We still need to remove the seektable related mallocs. Please report if any AAC or ALAC files stop playing in Rockbox after this commit - but it is not expected to cause problems.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15861 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 51 insertions, 53 deletions

diff --git a/apps/codecs/libalac/alac.c b/apps/codecs/libalac/alac.c
index f8e4df8b1d..d5d9be17f7 100644
--- a/apps/codecs/libalac/alac.c
+++ b/apps/codecs/libalac/alac.c
@@ -38,23 +38,25 @@
 #include "../codec.h"
 #include "decomp.h"
 
-#define _Swap32(v) do { \
-                   v = (((v) & 0x000000FF) << 0x18) | \
-                       (((v) & 0x0000FF00) << 0x08) | \
-                       (((v) & 0x00FF0000) >> 0x08) | \
-                       (((v) & 0xFF000000) >> 0x18); } while(0)
-
-#define _Swap16(v) do { \
-                   v = (((v) & 0x00FF) << 0x08) | \
-                       (((v) & 0xFF00) >> 0x08); } while (0)
-
 int16_t predictor_coef_table[32] IBSS_ATTR;
 int16_t predictor_coef_table_a[32] IBSS_ATTR;
 int16_t predictor_coef_table_b[32] IBSS_ATTR;
 
+
+/* Endian/aligment safe functions - only used in alac_set_info() */
+static uint32_t get_uint32be(unsigned char* p)
+{
+  return((p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3]);
+}
+
+static uint16_t get_uint16be(unsigned char* p)
+{
+  return((p[0]<<8) | p[1]);
+}
+
 void alac_set_info(alac_file *alac, char *inputbuffer)
 {
-  char *ptr = inputbuffer;
+  unsigned char* ptr = (unsigned char*)inputbuffer;
   ptr += 4; /* size */
   ptr += 4; /* frma */
   ptr += 4; /* alac */
@@ -63,42 +65,22 @@ void alac_set_info(alac_file *alac, char *inputbuffer)
 
   ptr += 4; /* 0 ? */
 
-  alac->setinfo_max_samples_per_frame = *(uint32_t*)ptr; /* buffer size / 2 ? */
-#ifdef ROCKBOX_LITTLE_ENDIAN
-  _Swap32(alac->setinfo_max_samples_per_frame);
-#endif
+  alac->setinfo_max_samples_per_frame = get_uint32be(ptr); /* buffer size / 2 ? */
   ptr += 4;
-  alac->setinfo_7a = *(uint8_t*)ptr;
+  alac->setinfo_7a = *ptr++;
+  alac->setinfo_sample_size = *ptr++;
+  alac->setinfo_rice_historymult = *ptr++;
+  alac->setinfo_rice_initialhistory = *ptr++;
+  alac->setinfo_rice_kmodifier = *ptr++;
+  alac->setinfo_7f = *ptr++;
   ptr += 1;
-  alac->setinfo_sample_size = *(uint8_t*)ptr;
-  ptr += 1;
-  alac->setinfo_rice_historymult = *(uint8_t*)ptr;
-  ptr += 1;
-  alac->setinfo_rice_initialhistory = *(uint8_t*)ptr;
-  ptr += 1;
-  alac->setinfo_rice_kmodifier = *(uint8_t*)ptr;
-  ptr += 1;
-  alac->setinfo_7f = *(uint8_t*)ptr;
-  ptr += 1;
-  alac->setinfo_80 = *(uint16_t*)ptr;
-#ifdef ROCKBOX_LITTLE_ENDIAN
-  _Swap16(alac->setinfo_80);
-#endif
+  alac->setinfo_80 = get_uint16be(ptr);
   ptr += 2;
-  alac->setinfo_82 = *(uint32_t*)ptr;
-#ifdef ROCKBOX_LITTLE_ENDIAN
-  _Swap32(alac->setinfo_82);
-#endif
+  alac->setinfo_82 = get_uint32be(ptr);
   ptr += 4;
-  alac->setinfo_86 = *(uint32_t*)ptr;
-#ifdef ROCKBOX_LITTLE_ENDIAN
-  _Swap32(alac->setinfo_86);
-#endif
+  alac->setinfo_86 = get_uint32be(ptr);
   ptr += 4;
-  alac->setinfo_8a_rate = *(uint32_t*)ptr;
-#ifdef ROCKBOX_LITTLE_ENDIAN
-  _Swap32(alac->setinfo_8a_rate);
-#endif
+  alac->setinfo_8a_rate = get_uint32be(ptr);
   ptr += 4;
 }
 
diff --git a/apps/codecs/libm4a/demux.c b/apps/codecs/libm4a/demux.c
index 634bb4ffca..912e7327e7 100644
--- a/apps/codecs/libm4a/demux.c
+++ b/apps/codecs/libm4a/demux.c
@@ -150,14 +150,15 @@ static bool read_chunk_esds(qtmovie_t *qtmovie, size_t chunk_len)
     
     /* read length */
     qtmovie->res->codecdata_len = mp4ff_read_mp4_descr_length(qtmovie->stream);
-    qtmovie->res->codecdata = malloc(qtmovie->res->codecdata_len);
-    if (qtmovie->res->codecdata)
+    if (qtmovie->res->codecdata_len > MAX_CODECDATA_SIZE)
     {
-        stream_read(qtmovie->stream, qtmovie->res->codecdata_len, qtmovie->res->codecdata);
-    } else {
-        qtmovie->res->codecdata_len = 0;
+        DEBUGF("codecdata too large (%d) in esds\n", 
+               (int)qtmovie->res->codecdata_len);
+        return false;
     }
 
+    stream_read(qtmovie->stream, qtmovie->res->codecdata_len, qtmovie->res->codecdata);
+
     /* will skip the remainder of the atom */
     return true;
 }
@@ -225,19 +226,21 @@ static bool read_chunk_stsd(qtmovie_t *qtmovie, size_t chunk_len)
 
           /* 12 = audio format atom, 8 = padding */
           qtmovie->res->codecdata_len = entry_remaining + 12 + 8;
-          qtmovie->res->codecdata = malloc(qtmovie->res->codecdata_len);
-          
-          if (!qtmovie->res->codecdata)
+          if (qtmovie->res->codecdata_len > MAX_CODECDATA_SIZE)
           {
-             DEBUGF("stsd too large\n");
-             return false;
+             DEBUGF("codecdata too large (%d) in stsd\n", 
+                    (int)qtmovie->res->codecdata_len);
           }
 
           memset(qtmovie->res->codecdata, 0, qtmovie->res->codecdata_len);
           /* audio format atom */
+#if 0
+          /* The ALAC decoder skips these bytes, so there is no need to store them,
+             and this code isn't endian/alignment safe */
           ((unsigned int*)qtmovie->res->codecdata)[0] = 0x0c000000;
           ((unsigned int*)qtmovie->res->codecdata)[1] = MAKEFOURCC('a','m','r','f');
           ((unsigned int*)qtmovie->res->codecdata)[2] = MAKEFOURCC('c','a','l','a');
+#endif
 
           stream_read(qtmovie->stream,
                   entry_remaining,
diff --git a/apps/codecs/libm4a/m4a.h b/apps/codecs/libm4a/m4a.h
index 401cff3b7a..a4d4dc0f79 100644
--- a/apps/codecs/libm4a/m4a.h
+++ b/apps/codecs/libm4a/m4a.h
@@ -23,6 +23,19 @@
 #include <codecs.h>
 #include <inttypes.h>
 
+/* AAC codecdata appears to always be less than 8 bytes - see
+   AudioSpecificConfig2 in libfaad/mp4.c
+
+   ALAC codecdata appears to always be 44 bytes (see alac_set_info in
+   libalac/alac.c) but my test file contains 56 bytes.
+
+   So we go safe and round up to 64 bytes - if we find more than this,
+   we give an error (even though we could possibly continue), so we
+   can increase this buffer.
+*/
+
+#define MAX_CODECDATA_SIZE  64
+
 typedef struct {
   struct codec_api* ci;
   int eof;
@@ -57,7 +70,7 @@ typedef struct
     uint32_t num_sample_byte_sizes;
 
     uint32_t codecdata_len;
-    void *codecdata;
+    uint8_t codecdata[MAX_CODECDATA_SIZE];
 
     int mdat_offset;
     uint32_t mdat_len;