From f8a33203d86093dbaac43f00f99b3b4ec5ce2f96 Mon Sep 17 00:00:00 2001
From: Buschel <Buschel@a1c6a512-1295-4272-9138-f99709370657>
Date: Thu, 3 Feb 2011 09:23:04 +0000
Subject: [PATCH] Changes in m4a parser: The metadata (e.g. sampling rate) for
 alac and aac must read from their dedicated metadata atom. Otherwise there
 might be wrong settings used. This patch also adds (commented) code which
 enables parsing for an alac metadata atom if neccessary. I have several
 sample files which require such parsing to find the metadata atom. Fixes
 FS#11719.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29201 a1c6a512-1295-4272-9138-f99709370657
---
 apps/metadata/mp4.c | 72 +++++++++++++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 33 deletions(-)

diff --git a/apps/metadata/mp4.c b/apps/metadata/mp4.c
index 9ae174af7..1ef3701e3 100644
--- a/apps/metadata/mp4.c
+++ b/apps/metadata/mp4.c
@@ -675,48 +675,54 @@ static bool read_mp4_container(int fd, struct mp3entry* id3,
             break;
 
         case MP4_mp4a:
+            {
+                uint32_t subsize;
+                uint32_t subtype;
+
+                /* Move to the next expected mp4 atom. */
+                lseek(fd, 28, SEEK_CUR);
+                read_mp4_atom(fd, &subsize, &subtype, size);
+                size -= 36;
+
+                if (subtype == MP4_esds)
+                {
+                    /* Read esds metadata and return if AAC-HE/SBR is used. */
+                    if (read_mp4_esds(fd, id3, &size))
+                        id3->codectype = AFMT_MP4_AAC_HE;
+                    else
+                        id3->codectype = AFMT_MP4_AAC;
+                }
+            }
+            break;
+
         case MP4_alac:
             {
                 uint32_t frequency;
-
-                lseek(fd, 22, SEEK_CUR);
-                read_uint32be(fd, &frequency);
-                size -= 26;
-                id3->frequency = frequency;
-                
-                if (type == MP4_mp4a)
+                uint32_t subsize;
+                uint32_t subtype;
+
+                /* Move to the next expected mp4 atom. */
+                lseek(fd, 28, SEEK_CUR);
+                read_mp4_atom(fd, &subsize, &subtype, size);
+                size -= 36;
+#if 0
+                /* We might need to parse for the alac metadata atom. */
+                while (!((subsize==28) && (subtype==MP4_alac)) && (size>0))
                 {
-                    uint32_t subsize;
-                    uint32_t subtype;
-                    bool sbr_used;
-
-                    /* Get frequency from the decoder info tag, if possible. */
-                    lseek(fd, 2, SEEK_CUR);
-                    /* The esds atom is a part of the mp4a atom, so ignore 
-                     * the returned size (it's already accounted for).
-                     */
+                    lseek(fd, -7, SEEK_CUR);
                     read_mp4_atom(fd, &subsize, &subtype, size);
-                    size -= 10;
-                    
-                    id3->codectype = AFMT_MP4_AAC;
-                    if (subtype == MP4_esds)
-                    {
-                        sbr_used = read_mp4_esds(fd, id3, &size);
-                        if (sbr_used)
-                        {
-                            id3->codectype = AFMT_MP4_AAC_HE;
-                            if (SBR_upsampling_used)
-                                DEBUGF("MP4: AAC-HE, SBR upsampling\n");
-                            else
-                                DEBUGF("MP4: AAC-HE, SBR\n");
-                        }
-                    }
+                    size -= 1;
+                    errno = 0; /* will most likely be set while parsing */
                 }
-                else
+#endif
+                if (subtype == MP4_alac)
                 {
+                    lseek(fd, 24, SEEK_CUR);
+                    read_uint32be(fd, &frequency);
+                    size -= 28;
+                    id3->frequency = frequency;
                     id3->codectype = AFMT_MP4_ALAC;
                 }
-
             }
             break;
 
-- 
2.11.4.GIT