qtmux: support for ALAC

Fixes #580731.

gst/qtmux/atoms.c

@@ -3157,6 +3157,16 @@ build_mov_aac_extension (AtomTRAK * trak, const GstBuffer * codec_data)
   return build_mov_wave_extension (trak, FOURCC_mp4a, mp4a, esds, TRUE);
 }
 
+AtomInfo *
+build_mov_alac_extension (AtomTRAK * trak, const GstBuffer * codec_data)
+{
+  AtomInfo *alac;
+
+  alac = build_codec_data_extension (FOURCC_alac, codec_data);
+
+  return build_mov_wave_extension (trak, FOURCC_alac, NULL, alac, TRUE);
+}
+
 AtomInfo *
 build_fiel_extension (gint fields)
 {

gst/qtmux/atoms.h

@@ -721,6 +721,7 @@ void atom_trak_set_video_type (AtomTRAK * trak, AtomsContext * context,
 
 AtomInfo *   build_codec_data_extension  (guint32 fourcc, const GstBuffer * codec_data);
 AtomInfo *   build_mov_aac_extension     (AtomTRAK * trak, const GstBuffer * codec_data);
+AtomInfo *   build_mov_alac_extension    (AtomTRAK * trak, const GstBuffer * codec_data);
 AtomInfo *   build_esds_extension        (AtomTRAK * trak, guint8 object_type,
                                           guint8 stream_type, const GstBuffer * codec_data);
 AtomInfo *   build_jp2h_extension        (AtomTRAK * trak, gint width, gint height,

gst/qtmux/gstqtmux.c

@@ -2065,6 +2065,35 @@ gst_qt_mux_audio_sink_set_caps (GstPad * pad, GstCaps * caps)
     entry.compression_id = -1;
 
     ext_atom = build_ima_adpcm_extension (channels, rate, blocksize);
+  } else if (strcmp (mimetype, "audio/x-alac") == 0) {
+    GstBuffer *codec_config;
+    gint len;
+
+    entry.fourcc = FOURCC_alac;
+    /* let's check if codec data already comes with 'alac' atom prefix */
+    if (!codec_data || (len = GST_BUFFER_SIZE (codec_data)) < 28) {
+      GST_DEBUG_OBJECT (qtmux, "broken caps, codec data missing");
+      goto refuse_caps;
+    }
+    if (GST_READ_UINT32_LE (GST_BUFFER_DATA (codec_data) + 4) == FOURCC_alac) {
+      len -= 8;
+      codec_config = gst_buffer_create_sub ((GstBuffer *) codec_data, 8, len);
+    } else {
+      codec_config = gst_buffer_ref ((GstBuffer *) codec_data);
+    }
+    if (len != 28) {
+      /* does not look good, but perhaps some trailing unneeded stuff */
+      GST_WARNING_OBJECT (qtmux, "unexpected codec-data size, possibly broken");
+    }
+    if (format == GST_QT_MUX_FORMAT_QT)
+      ext_atom = build_mov_alac_extension (qtpad->trak, codec_config);
+    else
+      ext_atom = build_codec_data_extension (FOURCC_alac, codec_config);
+    /* set some more info */
+    entry.bytes_per_sample = 2;
+    entry.samples_per_packet =
+        GST_READ_UINT32_BE (GST_BUFFER_DATA (codec_config) + 4);
+    gst_buffer_unref (codec_config);
   }
 
   if (!entry.fourcc)

gst/qtmux/gstqtmuxmap.c

@@ -137,6 +137,9 @@
   "block_align = (int)[64, 8096], " \
   COMMON_AUDIO_CAPS(2, MAX)
 
+#define ALAC_CAPS \
+  "audio/x-alac, " \
+  COMMON_AUDIO_CAPS(2, MAX)
 
 /* FIXME 0.11 - take a look at bugs #580005 and #340375 */
 GstQTMuxFormatProp gst_qt_mux_format_list[] = {
@@ -166,7 +169,8 @@ GstQTMuxFormatProp gst_qt_mux_format_list[] = {
             MP3_CAPS " ; "
             AAC_CAPS " ; "
             ADPCM_CAPS " ; "
-            "audio/x-alaw, " COMMON_AUDIO_CAPS (2, MAX) "; " AMR_CAPS)
+            "audio/x-alaw, " COMMON_AUDIO_CAPS (2, MAX) "; "
+            AMR_CAPS " ; " ALAC_CAPS)
       }
   ,
   /* ISO 14496-14: mp42 as ISO base media extension
@@ -179,7 +183,7 @@ GstQTMuxFormatProp gst_qt_mux_format_list[] = {
         GST_STATIC_CAPS ("video/quicktime, variant = (string) iso"),
         GST_STATIC_CAPS (MPEG4V_CAPS "; " H264_CAPS ";"
             "video/x-mp4-part," COMMON_VIDEO_CAPS),
-        GST_STATIC_CAPS (MP3_CAPS "; " AAC_CAPS)
+        GST_STATIC_CAPS (MP3_CAPS "; " AAC_CAPS " ; " ALAC_CAPS)
       }
   ,
   /* 3GPP Technical Specification 26.244 V7.3.0