From e837d8ddaca6f72e29c69833bd46a0454d36221f Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Fri, 15 Mar 2013 07:49:47 +0100
Subject: [PATCH] demux_mkv: support ALAC

Test sample was produced with ffmpeg. Extradata handling closely follows
libavformat/matroskadec.c.
---
 demux/codec_tags.c |  1 +
 demux/demux_mkv.c  | 11 +++++++++++
 demux/matroska.h   |  1 +
 3 files changed, 13 insertions(+)

diff --git a/demux/codec_tags.c b/demux/codec_tags.c
index 8f535ba487..70b7a9a26e 100644
--- a/demux/codec_tags.c
+++ b/demux/codec_tags.c
@@ -104,6 +104,7 @@ static const struct mp_codec_tag mp_audio_codec_tags[] = {
     {0xfffe                   , "pcm"},
     // ------- internal mplayer FourCCs ------
     {MKTAG('O', 'p', 'u', 's'), "opus"}, // demux_mkv.c
+    {MKTAG('a', 'L', 'a', 'C'), "alac"}, // demux_mkv.c
     {MKTAG('S', 'a', 'd', 'x'), "adpcm_adx"},
     {MKTAG('A', 'M', 'V', 'A'), "adpcm_ima_amv"},
     {MKTAG('R', 'o', 'Q', 'A'), "roq_dpcm"},
diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index 012ddba516..3917621384 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -1321,6 +1321,7 @@ static struct mkv_audio_tag {
     { MKV_A_WAVPACK,   0, mmioFOURCC('W', 'V', 'P', 'K') },
     { MKV_A_TRUEHD,    0, mmioFOURCC('T', 'R', 'H', 'D') },
     { MKV_A_FLAC,      0, mmioFOURCC('f', 'L', 'a', 'C') },
+    { MKV_A_ALAC,      0, mmioFOURCC('a', 'L', 'a', 'C') },
     { MKV_A_REAL28,    0, mmioFOURCC('2', '8', '_', '8') },
     { MKV_A_REALATRC,  0, mmioFOURCC('a', 't', 'r', 'c') },
     { MKV_A_REALCOOK,  0, mmioFOURCC('c', 'o', 'o', 'k') },
@@ -1549,6 +1550,16 @@ static int demux_mkv_open_audio(demuxer_t *demuxer, mkv_track_t *track,
             sh_a->codecdata_len = size;
             memcpy(sh_a->codecdata, ptr, size);
         }
+    } else if (!strcmp(track->codec_id, MKV_A_ALAC)) {
+        if (track->private_size && track->private_size < 10000000) {
+            sh_a->codecdata_len = track->private_size + 12;
+            sh_a->codecdata = malloc(sh_a->codecdata_len);
+            char *data = sh_a->codecdata;
+            AV_WB32(data + 0, sh_a->codecdata_len);
+            memcpy(data + 4, "alac", 4);
+            AV_WB32(data + 8, 0);
+            memcpy(data + 12, track->private_data, track->private_size);
+        }
     } else if (track->a_formattag == mmioFOURCC('W', 'V', 'P', 'K') ||
                track->a_formattag == mmioFOURCC('T', 'R', 'H', 'D')) {
     copy_private_data:
diff --git a/demux/matroska.h b/demux/matroska.h
index 2d424e2a40..be28f34282 100644
--- a/demux/matroska.h
+++ b/demux/matroska.h
@@ -52,6 +52,7 @@
 #define MKV_A_QDMC       "A_QUICKTIME/QDMC"
 #define MKV_A_QDMC2      "A_QUICKTIME/QDM2"
 #define MKV_A_FLAC       "A_FLAC"
+#define MKV_A_ALAC       "A_ALAC"
 #define MKV_A_TTA1       "A_TTA1"
 #define MKV_A_WAVPACK    "A_WAVPACK4"
 #define MKV_A_TRUEHD     "A_TRUEHD"