qtmux: WIP CC support

1 files changed, 121 insertions, 18 deletions

diff --git a/gst/isomp4/gstqtmux.c b/gst/isomp4/gstqtmux.c
index 9c2609c09..81eee0d9b 100644
--- a/gst/isomp4/gstqtmux.c
+++ b/gst/isomp4/gstqtmux.c
@@ -133,6 +133,7 @@
 #include <gst/base/gstbitreader.h>
 #include <gst/audio/audio.h>
 #include <gst/video/video.h>
+#include <gst/video/video-anc.h>
 #include <gst/tag/tag.h>
 #include <gst/pbutils/pbutils.h>
 
@@ -873,34 +874,128 @@ gst_qt_mux_prepare_jpc_buffer (GstQTPad * qtpad, GstBuffer * buf,
   return newbuf;
 }
 
+static gsize
+extract_608_field_from_cc_data (const guint8 * ccdata, gsize ccdata_size,
+    guint field, guint8 ** res)
+{
+  guint8 *storage;
+  gsize storage_size = 128;
+  gsize i, res_size = 0;
+
+  storage = g_malloc0 (storage_size);
+
+  /* Iterate over the ccdata and put the corresponding tuples for the given field
+   * in the storage */
+  for (i = 0; i < ccdata_size; i += 3) {
+    if ((field == 1 && ccdata[i * 3] == 0xfc) ||
+        (field == 2 && ccdata[i * 3] == 0xfd)) {
+      GST_DEBUG ("Storing matching cc for field %d : 0x%02x 0x%02x", field,
+          ccdata[i * 3 + 1], ccdata[i * 3 + 2]);
+      if (res_size >= storage_size) {
+        storage_size += 128;
+        storage = g_realloc (storage, storage_size);
+      }
+      storage[res_size] = ccdata[i * 3 + 1];
+      storage[res_size + 1] = ccdata[i * 3 + 2];
+      res_size += 2;
+    }
+  }
+
+  if (res_size == 0) {
+    g_free (storage);
+    *res = NULL;
+    return 0;
+  }
+
+  *res = storage;
+  return res_size;
+}
+
+
 static GstBuffer *
-gst_qt_mux_prepare_cdat_buffer (GstQTPad * qtpad, GstBuffer * buf,
+gst_qt_mux_prepare_caption_buffer (GstQTPad * qtpad, GstBuffer * buf,
     GstQTMux * qtmux)
 {
-  GstBuffer *newbuf;
+  GstBuffer *newbuf = NULL;
   GstMapInfo map, inmap;
   gsize size;
 
-  GST_LOG_OBJECT (qtmux, "Preparing cdat buffer");
-
   if (buf == NULL)
     return NULL;
 
   size = gst_buffer_get_size (buf);
-  GST_LOG_OBJECT (qtmux, "Preparing buffer of size %" G_GSIZE_FORMAT, size + 8);
-  newbuf = gst_buffer_new_and_alloc (size + 8);
+  gst_buffer_map (buf, &inmap, GST_MAP_READ);
 
-  /* Let's copy over all metadata and not the memory */
-  gst_buffer_copy_into (newbuf, buf, GST_BUFFER_COPY_METADATA, 0, size);
+  GST_LOG_OBJECT (qtmux,
+      "Preparing caption buffer %" GST_FOURCC_FORMAT " size:%" G_GSIZE_FORMAT,
+      GST_FOURCC_ARGS (qtpad->fourcc), size);
 
-  gst_buffer_map (newbuf, &map, GST_MAP_WRITE);
-  gst_buffer_map (buf, &inmap, GST_MAP_READ);
+  switch (qtpad->fourcc) {
+    case FOURCC_c608:
+    {
+      guint8 *cdat, *cdt2;
+      gsize cdat_size, cdt2_size, total_size = 0;
+      gsize write_offs = 0;
+
+      cdat_size = extract_608_field_from_cc_data (map.data, map.size, 1, &cdat);
+      cdt2_size = extract_608_field_from_cc_data (map.data, map.size, 2, &cdt2);
+
+      if (cdat_size)
+        total_size += cdat_size + 8;
+      if (cdt2_size)
+        total_size += cdt2_size + 8;
+      if (total_size == 0) {
+        GST_DEBUG_OBJECT (qtmux, "No 608 data ?");
+        /* FIXME : We might want to *always* store something, even if
+         * it's "empty" CC (i.e. 0x80 0x80) */
+        break;
+      }
 
-  GST_WRITE_UINT32_BE (map.data, map.size);
-  GST_WRITE_UINT32_LE (map.data + 4, FOURCC_cdat);
-  memcpy (map.data + 8, inmap.data, inmap.size);
+      newbuf = gst_buffer_new_and_alloc (total_size);
+      /* Let's copy over all metadata and not the memory */
+      gst_buffer_copy_into (newbuf, buf, GST_BUFFER_COPY_METADATA, 0, size);
+
+      gst_buffer_map (newbuf, &map, GST_MAP_WRITE);
+      if (cdat_size) {
+        GST_WRITE_UINT32_BE (map.data, cdat_size + 8);
+        GST_WRITE_UINT32_LE (map.data + 4, FOURCC_cdat);
+        memcpy (map.data + 8, cdat, cdat_size);
+        write_offs = cdat_size + 8;
+        g_free (cdat);
+      }
+      if (cdt2_size) {
+        GST_WRITE_UINT32_BE (map.data + write_offs, cdt2_size + 8);
+        GST_WRITE_UINT32_LE (map.data + write_offs + 4, FOURCC_cdt2);
+        memcpy (map.data + write_offs + 8, cdt2, cdt2_size);
+        g_free (cdt2);
+      }
+      gst_buffer_unmap (newbuf, &map);
+      break;
+    }
+      break;
+    case FOURCC_c708:
+    {
+      /* Take the whole CDP */
+      newbuf = gst_buffer_new_and_alloc (size + 8);
+
+      /* Let's copy over all metadata and not the memory */
+      gst_buffer_copy_into (newbuf, buf, GST_BUFFER_COPY_METADATA, 0, size);
+
+      gst_buffer_map (newbuf, &map, GST_MAP_WRITE);
+
+      GST_WRITE_UINT32_BE (map.data, map.size + 8);
+      GST_WRITE_UINT32_LE (map.data + 4, FOURCC_ccdp);
+      memcpy (map.data + 8, inmap.data, inmap.size);
+
+      gst_buffer_unmap (newbuf, &map);
+      break;
+    }
+    default:
+      /* theoretically this should never happen, but let's keep this here in case */
+      GST_WARNING_OBJECT (qtmux, "Unknown caption format");
+      break;
+  }
 
-  gst_buffer_unmap (newbuf, &map);
   gst_buffer_unmap (buf, &inmap);
   gst_buffer_unref (buf);
 
@@ -5829,6 +5924,7 @@ gst_qt_mux_caption_sink_set_caps (GstQTPad * qtpad, GstCaps * caps)
   GstQTMux *qtmux = GST_QT_MUX_CAST (gst_pad_get_parent (pad));
   GstStructure *structure;
   guint32 fourcc_entry;
+  guint32 timescale;
 
   if (qtpad->fourcc)
     return gst_qt_mux_can_renegotiate (qtmux, pad, caps);
@@ -5840,12 +5936,12 @@ gst_qt_mux_caption_sink_set_caps (GstQTPad * qtpad, GstCaps * caps)
   qtpad->is_out_of_order = FALSE;
   qtpad->sync = FALSE;
   qtpad->sparse = TRUE;
-  /* Closed caption data is within a cdat atom */
-  qtpad->prepare_buf_func = gst_qt_mux_prepare_cdat_buffer;
+  /* Closed caption data are within atoms */
+  qtpad->prepare_buf_func = gst_qt_mux_prepare_caption_buffer;
 
   structure = gst_caps_get_structure (caps, 0);
 
-
+  /* We know we only handle 608,format=cc_data and 708,format=cdp */
   if (gst_structure_has_name (structure, "closedcaption/x-cea-608")) {
     fourcc_entry = FOURCC_c608;
   } else if (gst_structure_has_name (structure, "closedcaption/x-cea-708")) {
@@ -5853,10 +5949,17 @@ gst_qt_mux_caption_sink_set_caps (GstQTPad * qtpad, GstCaps * caps)
   } else
     goto refuse_caps;
 
+  /* FIXME: Get the timescale from the video track ? */
+  timescale = gst_qt_mux_pad_get_timescale (GST_QT_MUX_PAD_CAST (pad));
+  if (!timescale && qtmux->trak_timescale)
+    timescale = qtmux->trak_timescale;
+  else if (!timescale)
+    timescale = 30000;
+
   qtpad->fourcc = fourcc_entry;
   qtpad->trak_ste =
       (SampleTableEntry *) atom_trak_set_caption_type (qtpad->trak,
-      qtmux->context, fourcc_entry);
+      qtmux->context, timescale, fourcc_entry);
 
   gst_object_unref (qtmux);
   return TRUE;