gst/mpegvideoparse/: Move the MPEG specific byte parsing into the mpegpacketiser code.

Original commit message from CVS:
* gst/mpegvideoparse/mpegpacketiser.c: (mpeg_util_find_start_code),
(collect_packets), (set_par_from_dar), (set_fps_from_code),
(mpeg_util_parse_extension_packet), (mpeg_util_parse_sequence_hdr),
(mpeg_util_parse_picture_hdr):
* gst/mpegvideoparse/mpegpacketiser.h:
* gst/mpegvideoparse/mpegvideoparse.c:
(mpegvideoparse_handle_sequence), (mpegvideoparse_handle_picture),
(mpegvideoparse_drain_avail), (gst_mpegvideoparse_chain),
(mpv_parse_sink_event), (plugin_init):
* gst/mpegvideoparse/mpegvideoparse.h:
Move the MPEG specific byte parsing into the mpegpacketiser code.
Add parsing of picture types, that just feeds into a debug message
for now.
Fix some 64-bit format strings.

1 files changed, 178 insertions, 3 deletions

diff --git a/gst/mpegvideoparse/mpegpacketiser.c b/gst/mpegvideoparse/mpegpacketiser.c
index 5c054ed8..318805fd 100644
--- a/gst/mpegvideoparse/mpegpacketiser.c
+++ b/gst/mpegvideoparse/mpegpacketiser.c
@@ -87,7 +87,7 @@ mpeg_packetiser_flush (MPEGPacketiser * p)
 }
 
 guint8 *
-mpeg_find_start_code (guint32 * sync_word, guint8 * cur, guint8 * end)
+mpeg_util_find_start_code (guint32 * sync_word, guint8 * cur, guint8 * end)
 {
   guint32 code = *sync_word;
 
@@ -351,7 +351,7 @@ collect_packets (MPEGPacketiser * p, GstBuffer * buf)
   guint8 *cur;
   guint8 *end = GST_BUFFER_DATA (buf) + GST_BUFFER_SIZE (buf);
 
-  cur = mpeg_find_start_code (&(p->sync_word), GST_BUFFER_DATA (buf), end);
+  cur = mpeg_util_find_start_code (&(p->sync_word), GST_BUFFER_DATA (buf), end);
   while (cur != NULL) {
     /* Calculate the offset as tracked since the last flush. Note that cur
      * points to the last byte of the sync word, so we adjust by -3 to get the
@@ -359,7 +359,7 @@ collect_packets (MPEGPacketiser * p, GstBuffer * buf)
     guint64 offset = p->tracked_offset + (cur - GST_BUFFER_DATA (buf) - 3);
 
     handle_packet (p, offset, *cur);
-    cur = mpeg_find_start_code (&(p->sync_word), cur, end);
+    cur = mpeg_util_find_start_code (&(p->sync_word), cur, end);
   }
 }
 
@@ -436,3 +436,178 @@ mpeg_packetiser_next_block (MPEGPacketiser * p)
   else
     p->first_block_idx = next;
 }
+
+/* Set the Pixel Aspect Ratio in our hdr from a DAR code in the data */
+static void
+set_par_from_dar (MPEGSeqHdr * hdr, guint8 asr_code)
+{
+  /* Pixel_width = DAR_width * display_vertical_size */
+  /* Pixel_height = DAR_height * display_horizontal_size */
+  switch (asr_code) {
+    case 0x02:                 /* 3:4 DAR = 4:3 pixels */
+      hdr->par_w = 4 * hdr->height;
+      hdr->par_h = 3 * hdr->width;
+      break;
+    case 0x03:                 /* 9:16 DAR */
+      hdr->par_w = 16 * hdr->height;
+      hdr->par_h = 9 * hdr->width;
+      break;
+    case 0x04:                 /* 1:2.21 DAR */
+      hdr->par_w = 221 * hdr->height;
+      hdr->par_h = 100 * hdr->width;
+      break;
+    case 0x01:                 /* Square pixels */
+    default:
+      hdr->par_w = hdr->par_h = 1;
+      break;
+  }
+}
+
+static void
+set_fps_from_code (MPEGSeqHdr * hdr, guint8 fps_code)
+{
+  const gint framerates[][2] = {
+    {30, 1}, {24000, 1001}, {24, 1}, {25, 1},
+    {30000, 1001}, {30, 1}, {50, 1}, {60000, 1001},
+    {60, 1}, {30, 1}
+  };
+
+  if (fps_code < 10) {
+    hdr->fps_n = framerates[fps_code][0];
+    hdr->fps_d = framerates[fps_code][1];
+  } else {
+    /* Force a valid framerate */
+    hdr->fps_n = 30000;
+    hdr->fps_d = 1001;
+  }
+}
+
+static gboolean
+mpeg_util_parse_extension_packet (MPEGSeqHdr * hdr, guint8 * data, guint8 * end)
+{
+  guint8 ext_code;
+
+  if (G_UNLIKELY ((end - data - 1) < 1))
+    return FALSE;               /* short extension packet */
+
+  ext_code = data[0] >> 4;
+
+  switch (ext_code) {
+    case MPEG_PACKET_EXT_SEQUENCE:
+    {
+      /* Parse a Sequence Extension */
+      guint8 horiz_size_ext, vert_size_ext;
+      guint8 fps_n_ext, fps_d_ext;
+
+      if ((end - data - 1) < 6)
+        /* need at least 10 bytes, minus 4 for the start code 000001b5 */
+        return FALSE;
+
+      horiz_size_ext = ((data[1] << 1) & 0x02) | ((data[2] >> 7) & 0x01);
+      vert_size_ext = (data[2] >> 5) & 0x03;
+      fps_n_ext = (data[5] >> 5) & 0x03;
+      fps_d_ext = data[5] & 0x1f;
+
+      hdr->fps_n *= (fps_n_ext + 1);
+      hdr->fps_d *= (fps_d_ext + 1);
+      hdr->width += (horiz_size_ext << 12);
+      hdr->height += (vert_size_ext << 12);
+      break;
+    }
+    default:
+      break;
+  }
+
+  return TRUE;
+}
+
+gboolean
+mpeg_util_parse_sequence_hdr (MPEGSeqHdr * hdr, guint8 * data, guint8 * end)
+{
+  guint32 code;
+  guint8 dar_idx, fps_idx;
+  guint32 sync_word = 0xffffffff;
+  gboolean constrained_flag;
+  gboolean load_intra_flag;
+  gboolean load_non_intra_flag;
+
+  if (G_UNLIKELY ((end - data - 1) < 12))
+    return FALSE;               /* Too small to be a sequence header */
+
+  code = GST_READ_UINT32_BE (data);
+  if (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_SEQUENCE)))
+    return FALSE;
+
+  /* Skip the sync word */
+  data += 4;
+
+  /* Parse the MPEG 1 bits */
+  hdr->mpeg_version = 1;
+
+  code = GST_READ_UINT32_BE (data);
+  hdr->width = (code >> 20) & 0xfff;
+  hdr->height = (code >> 8) & 0xfff;
+
+  dar_idx = (code >> 4) & 0xf;
+  set_par_from_dar (hdr, dar_idx);
+  fps_idx = code & 0xf;
+  set_fps_from_code (hdr, fps_idx);
+
+  constrained_flag = (data[7] >> 2) & 0x01;
+  load_intra_flag = (data[7] >> 1) & 0x01;
+  if (load_intra_flag) {
+    if (G_UNLIKELY ((end - data - 1) < 64))
+      return FALSE;
+    data += 64;
+  }
+
+  load_non_intra_flag = data[7] & 0x01;
+  if (load_non_intra_flag) {
+    if (G_UNLIKELY ((end - data - 1) < 64))
+      return FALSE;
+    data += 64;
+  }
+
+  /* Advance past the rest of the MPEG-1 header */
+  data += 8;
+
+  /* Read MPEG-2 sequence extensions */
+  data = mpeg_util_find_start_code (&sync_word, data, end);
+  while (data != NULL) {
+    if (G_UNLIKELY ((end - data - 1) < 1))
+      return FALSE;
+
+    /* data points at the last byte of the start code */
+    if (data[0] == MPEG_PACKET_EXTENSION) {
+      if (!mpeg_util_parse_extension_packet (hdr, data + 1, end))
+        return FALSE;
+
+      hdr->mpeg_version = 2;
+    }
+    data = mpeg_util_find_start_code (&sync_word, data, end);
+  }
+
+  return TRUE;
+}
+
+gboolean
+mpeg_util_parse_picture_hdr (MPEGPictureHdr * hdr, guint8 * data, guint8 * end)
+{
+  guint32 code;
+
+  if (G_UNLIKELY ((end - data - 1) < 6))
+    return FALSE;               /* Packet too small */
+
+  code = GST_READ_UINT32_BE (data);
+  if (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_PICTURE)))
+    return FALSE;
+
+  /* Skip the start code */
+  data += 4;
+
+  hdr->pic_type = (data[1] >> 3) & 0x07;
+  if (hdr->pic_type == 0 || hdr->pic_type > 4)
+    return FALSE;               /* Corrupted picture packet */
+
+  return TRUE;
+}