From f8b87c8a05e4d694118b2097aee135d7bd26705d Mon Sep 17 00:00:00 2001
From: =?utf8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Thu, 28 Apr 2016 16:24:52 +0300
Subject: [PATCH] qtmux: Allow MPEG-1 Layer 1 and 2 in addition to 3 in MP4

Via the MPEG-4 Part 3 spec we can support the other layers too.
Also correct the samples per frame calculation for MP3 if it's MPEG-2 or
MPEG-2.5.

https://bugzilla.gnome.org/show_bug.cgi?id=765725
---
 gst/isomp4/gstqtmux.c    | 42 +++++++++++++++++++++++++-----------------
 gst/isomp4/gstqtmuxmap.c |  8 +++++++-
 2 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/gst/isomp4/gstqtmux.c b/gst/isomp4/gstqtmux.c
index 9ac7c77..5be830b 100644
--- a/gst/isomp4/gstqtmux.c
+++ b/gst/isomp4/gstqtmux.c
@@ -3461,30 +3461,38 @@ gst_qt_mux_audio_sink_set_caps (GstQTPad * qtpad, GstCaps * caps)
 
   /* now map onto a fourcc, and some extra properties */
   if (strcmp (mimetype, "audio/mpeg") == 0) {
-    gint mpegversion = 0;
+    gint mpegversion = 0, mpegaudioversion = 0;
     gint layer = -1;
 
     gst_structure_get_int (structure, "mpegversion", &mpegversion);
     switch (mpegversion) {
       case 1:
         gst_structure_get_int (structure, "layer", &layer);
-        switch (layer) {
-          case 3:
-            /* mp3 */
-            /* note: QuickTime player does not like mp3 either way in iso/mp4 */
-            if (format == GST_QT_MUX_FORMAT_QT)
-              entry.fourcc = FOURCC__mp3;
-            else {
-              entry.fourcc = FOURCC_mp4a;
-              ext_atom =
-                  build_esds_extension (qtpad->trak, ESDS_OBJECT_TYPE_MPEG1_P3,
-                  ESDS_STREAM_TYPE_AUDIO, codec_data, qtpad->avg_bitrate,
-                  qtpad->max_bitrate);
-            }
-            entry.samples_per_packet = 1152;
-            entry.bytes_per_sample = 2;
-            break;
+        gst_structure_get_int (structure, "mpegaudioversion",
+            &mpegaudioversion);
+
+        /* mp1/2/3 */
+        /* note: QuickTime player does not like mp3 either way in iso/mp4 */
+        if (format == GST_QT_MUX_FORMAT_QT)
+          entry.fourcc = FOURCC__mp3;
+        else {
+          entry.fourcc = FOURCC_mp4a;
+          ext_atom =
+              build_esds_extension (qtpad->trak, ESDS_OBJECT_TYPE_MPEG1_P3,
+              ESDS_STREAM_TYPE_AUDIO, codec_data, qtpad->avg_bitrate,
+              qtpad->max_bitrate);
+        }
+        if (layer == 1) {
+          g_warn_if_fail (format == GST_QT_MUX_FORMAT_MP4);
+          entry.samples_per_packet = 384;
+        } else if (layer == 2) {
+          g_warn_if_fail (format == GST_QT_MUX_FORMAT_MP4);
+          entry.samples_per_packet = 1152;
+        } else {
+          g_warn_if_fail (layer == 3);
+          entry.samples_per_packet = (mpegaudioversion <= 1) ? 1152 : 576;
         }
+        entry.bytes_per_sample = 2;
         break;
       case 4:
 
diff --git a/gst/isomp4/gstqtmuxmap.c b/gst/isomp4/gstqtmuxmap.c
index 61b11a4..5fabc92 100644
--- a/gst/isomp4/gstqtmuxmap.c
+++ b/gst/isomp4/gstqtmuxmap.c
@@ -104,6 +104,12 @@
   "layer = (int) 3, " \
   COMMON_AUDIO_CAPS (2, MAX)
 
+#define MP123_CAPS \
+  "audio/mpeg, " \
+  "mpegversion = (int) 1, " \
+  "layer = (int) [1, 3], " \
+  COMMON_AUDIO_CAPS (2, MAX)
+
 #define AAC_CAPS \
   "audio/mpeg, " \
   "mpegversion = (int) 4, " \
@@ -190,7 +196,7 @@ 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 "; "
+        GST_STATIC_CAPS (MP123_CAPS "; "
             AAC_CAPS " ; " AC3_CAPS " ; " ALAC_CAPS " ; " OPUS_CAPS),
       GST_STATIC_CAPS (TEXT_UTF8)}
   ,
-- 
2.7.4