vdpaumpegdec: use GstBitReader to parse bitstream

3 files changed, 405 insertions, 293 deletions

diff --git a/sys/vdpau/gstvdpmpegdecoder.c b/sys/vdpau/gstvdpmpegdecoder.c
index 006e6d41..fc7aa5a6 100644
--- a/sys/vdpau/gstvdpmpegdecoder.c
+++ b/sys/vdpau/gstvdpmpegdecoder.c
@@ -36,6 +36,8 @@
 #endif
 
 #include <gst/gst.h>
+#include <gst/base/gstbytereader.h>
+#include <gst/base/gstbitreader.h>
 #include <string.h>
 
 #include "mpegutil.h"
@@ -80,14 +82,82 @@ static void gst_vdp_mpeg_decoder_set_property (GObject * object,
 static void gst_vdp_mpeg_decoder_get_property (GObject * object,
     guint prop_id, GValue * value, GParamSpec * pspec);
 
+guint8 *
+mpeg_util_find_start_code (guint32 * sync_word, guint8 * cur, guint8 * end)
+{
+  guint32 code;
+
+  if (G_UNLIKELY (cur == NULL))
+    return NULL;
+
+  code = *sync_word;
+
+  while (cur < end) {
+    code <<= 8;
+
+    if (code == 0x00000100) {
+      /* Reset the sync word accumulator */
+      *sync_word = 0xffffffff;
+      return cur;
+    }
+
+    /* Add the next available byte to the collected sync word */
+    code |= *cur++;
+  }
+
+  *sync_word = code;
+  return NULL;
+}
+
+typedef struct
+{
+  GstBuffer *buffer;
+  guint8 *cur;
+  guint8 *end;
+} GstVdpMpegPacketizer;
+
+static GstBuffer *
+gst_vdp_mpeg_packetizer_get_next_packet (GstVdpMpegPacketizer * packetizer)
+{
+  guint32 sync_word = 0xffffff;
+  guint8 *packet_start;
+  guint8 *packet_end;
+
+  if (!packetizer->cur)
+    return NULL;
+
+  packet_start = packetizer->cur - 3;
+  packetizer->cur = packet_end = mpeg_util_find_start_code (&sync_word,
+      packetizer->cur, packetizer->end);
+
+  if (packet_end)
+    packet_end -= 3;
+  else
+    packet_end = packetizer->end;
+
+  return gst_buffer_create_sub (packetizer->buffer,
+      packet_start - GST_BUFFER_DATA (packetizer->buffer),
+      packet_end - packet_start);
+}
+
+static void
+gst_vdp_mpeg_packetizer_init (GstVdpMpegPacketizer * packetizer,
+    GstBuffer * buffer)
+{
+  guint32 sync_word = 0xffffffff;
+
+  packetizer->buffer = buffer;
+  packetizer->end = GST_BUFFER_DATA (buffer) + GST_BUFFER_SIZE (buffer);
+  packetizer->cur = mpeg_util_find_start_code (&sync_word,
+      GST_BUFFER_DATA (buffer), packetizer->end);
+}
+
 static gboolean
 gst_vdp_mpeg_decoder_set_caps (GstVdpDecoder * dec, GstCaps * caps)
 {
   GstVdpMpegDecoder *mpeg_dec;
   GstStructure *structure;
   const GValue *value;
-  GstBuffer *codec_data;
-  MPEGSeqHdr hdr = { 0, };
   VdpDecoderProfile profile;
   GstVdpDevice *device;
   VdpStatus status;
@@ -100,25 +170,44 @@ gst_vdp_mpeg_decoder_set_caps (GstVdpDecoder * dec, GstCaps * caps)
     profile = VDP_DECODER_PROFILE_MPEG1;
 
   value = gst_structure_get_value (structure, "codec_data");
-  codec_data = gst_value_get_buffer (value);
-  mpeg_util_parse_sequence_hdr (&hdr, GST_BUFFER_DATA (codec_data),
-      GST_BUFFER_DATA (codec_data) + GST_BUFFER_SIZE (codec_data));
-  if (mpeg_dec->version != 1) {
-    switch (hdr.profile) {
-      case 5:
-        profile = VDP_DECODER_PROFILE_MPEG2_SIMPLE;
-        break;
-      default:
-        profile = VDP_DECODER_PROFILE_MPEG2_MAIN;
-        break;
+  if (value) {
+    GstBuffer *codec_data, *buf;
+    GstVdpMpegPacketizer packetizer;
+
+    codec_data = gst_value_get_buffer (value);
+    gst_vdp_mpeg_packetizer_init (&packetizer, codec_data);
+    if ((buf = gst_vdp_mpeg_packetizer_get_next_packet (&packetizer))) {
+      MPEGSeqHdr hdr;
+
+      mpeg_util_parse_sequence_hdr (&hdr, buf);
+
+      memcpy (&mpeg_dec->vdp_info.intra_quantizer_matrix,
+          &hdr.intra_quantizer_matrix, 64);
+      memcpy (&mpeg_dec->vdp_info.non_intra_quantizer_matrix,
+          &hdr.non_intra_quantizer_matrix, 64);
+
+      gst_buffer_unref (buf);
+
+      if ((buf = gst_vdp_mpeg_packetizer_get_next_packet (&packetizer))) {
+        MPEGSeqExtHdr ext;
+
+        mpeg_util_parse_sequence_extension (&ext, buf);
+        if (mpeg_dec->version != 1) {
+          switch (ext.profile) {
+            case 5:
+              profile = VDP_DECODER_PROFILE_MPEG2_SIMPLE;
+              break;
+            default:
+              profile = VDP_DECODER_PROFILE_MPEG2_MAIN;
+              break;
+          }
+        }
+
+        gst_buffer_unref (buf);
+      }
     }
   }
 
-  memcpy (&mpeg_dec->vdp_info.intra_quantizer_matrix,
-      &hdr.intra_quantizer_matrix, 64);
-  memcpy (&mpeg_dec->vdp_info.non_intra_quantizer_matrix,
-      &hdr.non_intra_quantizer_matrix, 64);
-
   device = dec->device;
 
   if (mpeg_dec->decoder != VDP_INVALID_HANDLE) {
@@ -224,7 +313,7 @@ gst_vdp_mpeg_decoder_decode (GstVdpMpegDecoder * mpeg_dec,
 
 static gboolean
 gst_vdp_mpeg_decoder_parse_picture_coding (GstVdpMpegDecoder * mpeg_dec,
-    guint8 * data, guint8 * end)
+    GstBuffer * buffer)
 {
   GstVdpDecoder *dec;
   MPEGPictureExt pic_ext;
@@ -233,7 +322,7 @@ gst_vdp_mpeg_decoder_parse_picture_coding (GstVdpMpegDecoder * mpeg_dec,
   dec = GST_VDP_DECODER (mpeg_dec);
   info = &mpeg_dec->vdp_info;
 
-  if (!mpeg_util_parse_picture_coding_extension (&pic_ext, data, end))
+  if (!mpeg_util_parse_picture_coding_extension (&pic_ext, buffer))
     return FALSE;
 
   memcpy (&mpeg_dec->vdp_info.f_code, &pic_ext.f_code, 4);
@@ -252,16 +341,17 @@ gst_vdp_mpeg_decoder_parse_picture_coding (GstVdpMpegDecoder * mpeg_dec,
 
 static gboolean
 gst_vdp_mpeg_decoder_parse_sequence (GstVdpMpegDecoder * mpeg_dec,
-    guint8 * data, guint8 * end)
+    GstBuffer * buffer)
 {
   GstVdpDecoder *dec;
   MPEGSeqHdr hdr;
 
   dec = GST_VDP_DECODER (mpeg_dec);
 
-  if (!mpeg_util_parse_sequence_hdr (&hdr, data, end))
+  if (!mpeg_util_parse_sequence_hdr (&hdr, buffer))
     return FALSE;
 
+  g_debug ("här");
   memcpy (&mpeg_dec->vdp_info.intra_quantizer_matrix,
       &hdr.intra_quantizer_matrix, 64);
   memcpy (&mpeg_dec->vdp_info.non_intra_quantizer_matrix,
@@ -272,14 +362,14 @@ gst_vdp_mpeg_decoder_parse_sequence (GstVdpMpegDecoder * mpeg_dec,
 
 static gboolean
 gst_vdp_mpeg_decoder_parse_picture (GstVdpMpegDecoder * mpeg_dec,
-    guint8 * data, guint8 * end)
+    GstBuffer * buffer)
 {
   GstVdpDecoder *dec;
   MPEGPictureHdr pic_hdr;
 
   dec = GST_VDP_DECODER (mpeg_dec);
 
-  if (!mpeg_util_parse_picture_hdr (&pic_hdr, data, end))
+  if (!mpeg_util_parse_picture_hdr (&pic_hdr, buffer))
     return FALSE;
 
   if (pic_hdr.pic_type != I_FRAME
@@ -309,12 +399,12 @@ gst_vdp_mpeg_decoder_parse_picture (GstVdpMpegDecoder * mpeg_dec,
 }
 
 static gboolean
-gst_vdp_mpeg_decoder_parse_gop (GstVdpMpegDecoder * mpeg_dec, guint8 * data,
-    guint8 * end)
+gst_vdp_mpeg_decoder_parse_gop (GstVdpMpegDecoder * mpeg_dec,
+    GstBuffer * buffer)
 {
-  MPEGPictureGOP gop;
+  MPEGGop gop;
 
-  if (!mpeg_util_parse_picture_gop (&gop, data, end))
+  if (!mpeg_util_parse_gop (&gop, buffer))
     return FALSE;
 
   mpeg_dec->broken_gop = gop.broken_gop;
@@ -324,11 +414,11 @@ gst_vdp_mpeg_decoder_parse_gop (GstVdpMpegDecoder * mpeg_dec, guint8 * data,
 
 static gboolean
 gst_vdp_mpeg_decoder_parse_quant_matrix (GstVdpMpegDecoder * mpeg_dec,
-    guint8 * data, guint8 * end)
+    GstBuffer * buffer)
 {
   MPEGQuantMatrix qm;
 
-  if (!mpeg_util_parse_quant_matrix (&qm, data, end))
+  if (!mpeg_util_parse_quant_matrix (&qm, buffer))
     return FALSE;
 
   memcpy (&mpeg_dec->vdp_info.intra_quantizer_matrix,
@@ -355,8 +445,8 @@ static GstFlowReturn
 gst_vdp_mpeg_decoder_chain (GstPad * pad, GstBuffer * buffer)
 {
   GstVdpMpegDecoder *mpeg_dec;
-  guint8 *data, *end;
-  guint32 sync_word = 0xffffffff;
+  GstVdpMpegPacketizer packetizer;
+  GstBuffer *buf;
   GstFlowReturn ret = GST_FLOW_OK;
 
   mpeg_dec = GST_VDP_MPEG_DECODER (GST_OBJECT_PARENT (pad));
@@ -367,69 +457,70 @@ gst_vdp_mpeg_decoder_chain (GstPad * pad, GstBuffer * buffer)
     return GST_FLOW_OK;
   }
 
-  data = GST_BUFFER_DATA (buffer);
-  end = GST_BUFFER_DATA (buffer) + GST_BUFFER_SIZE (buffer);
+  gst_vdp_mpeg_packetizer_init (&packetizer, buffer);
+  while ((buf = gst_vdp_mpeg_packetizer_get_next_packet (&packetizer))) {
+    GstBitReader b_reader = GST_BIT_READER_INIT_FROM_BUFFER (buf);
+    guint32 sync_code;
+    guint8 start_code;
 
-  while ((data = mpeg_util_find_start_code (&sync_word, data, end))) {
-    guint8 *packet_start;
-    guint8 *packet_end;
+    /* skip sync_code */
+    gst_bit_reader_get_bits_uint32 (&b_reader, &sync_code, 8 * 3);
 
-    packet_start = data - 3;
-    packet_end = mpeg_util_find_start_code (&sync_word, data, end);
-    if (packet_end)
-      packet_end -= 3;
-    else
-      packet_end = end;
-
-    if (data[0] >= MPEG_PACKET_SLICE_MIN && data[0] <= MPEG_PACKET_SLICE_MAX) {
-      GstBuffer *subbuf;
+    /* start_code */
+    gst_bit_reader_get_bits_uint8 (&b_reader, &start_code, 8);
 
+    if (start_code >= MPEG_PACKET_SLICE_MIN
+        && start_code <= MPEG_PACKET_SLICE_MAX) {
       GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_SLICE");
-      subbuf =
-          gst_buffer_create_sub (buffer,
-          packet_start - GST_BUFFER_DATA (buffer), packet_end - packet_start);
-      gst_adapter_push (mpeg_dec->adapter, subbuf);
+
+      gst_buffer_ref (buf);
+      gst_adapter_push (mpeg_dec->adapter, buf);
       mpeg_dec->vdp_info.slice_count++;
     }
 
-    switch (data[0]) {
+    switch (start_code) {
       case MPEG_PACKET_PICTURE:
         GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_PICTURE");
 
-        if (!gst_vdp_mpeg_decoder_parse_picture (mpeg_dec, packet_start,
-                packet_end)) {
+        if (!gst_vdp_mpeg_decoder_parse_picture (mpeg_dec, buf)) {
           return GST_FLOW_OK;
         }
         break;
       case MPEG_PACKET_SEQUENCE:
         GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_SEQUENCE");
-        gst_vdp_mpeg_decoder_parse_sequence (mpeg_dec, packet_start,
-            packet_end);
+        gst_vdp_mpeg_decoder_parse_sequence (mpeg_dec, buf);
         break;
       case MPEG_PACKET_EXTENSION:
+      {
+        guint8 ext_code;
+
         GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_EXTENSION");
-        switch (read_bits (data + 1, 0, 4)) {
+
+        /* ext_code */
+        gst_bit_reader_get_bits_uint8 (&b_reader, &ext_code, 4);
+        switch (ext_code) {
           case MPEG_PACKET_EXT_PICTURE_CODING:
             GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_EXT_PICTURE_CODING");
-            gst_vdp_mpeg_decoder_parse_picture_coding (mpeg_dec, packet_start,
-                packet_end);
+            gst_vdp_mpeg_decoder_parse_picture_coding (mpeg_dec, buf);
             break;
           case MPEG_PACKET_EXT_QUANT_MATRIX:
             GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_EXT_QUANT_MATRIX");
-            gst_vdp_mpeg_decoder_parse_quant_matrix (mpeg_dec, packet_start,
-                packet_end);
+            gst_vdp_mpeg_decoder_parse_quant_matrix (mpeg_dec, buf);
             break;
           default:
             break;
         }
         break;
+      }
       case MPEG_PACKET_GOP:
         GST_DEBUG_OBJECT (mpeg_dec, "MPEG_PACKET_GOP");
-        gst_vdp_mpeg_decoder_parse_gop (mpeg_dec, packet_start, packet_end);
+        gst_vdp_mpeg_decoder_parse_gop (mpeg_dec, buf);
         break;
       default:
         break;
     }
+
+    gst_buffer_unref (buf);
   }
 
   if (mpeg_dec->vdp_info.slice_count > 0)
diff --git a/sys/vdpau/mpegutil.c b/sys/vdpau/mpegutil.c
index 08ae5c53..c35ad9fb 100644
--- a/sys/vdpau/mpegutil.c
+++ b/sys/vdpau/mpegutil.c
@@ -18,6 +18,7 @@
  * Boston, MA 02111-1307, USA.
  */
 
+#include <gst/base/gstbitreader.h>
 #include <string.h>
 
 #include "mpegutil.h"
@@ -53,58 +54,6 @@ guint8 mpeg2_scan[64] = {
   53, 60, 61, 54, 47, 55, 62, 63
 };
 
-guint8 bits[] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
-
-guint32
-read_bits (guint8 * buf, gint start_bit, gint n_bits)
-{
-  gint i;
-  guint32 ret = 0x00;
-
-  buf += start_bit / 8;
-  start_bit %= 8;
-
-  for (i = 0; i < n_bits; i++) {
-    guint32 tmp;
-
-    tmp = ((*buf & bits[start_bit]) >> (7 - start_bit));
-    ret = (ret | (tmp << (n_bits - i - 1)));
-    if (++start_bit == 8) {
-      buf += 1;
-      start_bit = 0;
-    }
-  }
-
-  return ret;
-}
-
-guint8 *
-mpeg_util_find_start_code (guint32 * sync_word, guint8 * cur, guint8 * end)
-{
-  guint32 code;
-
-  if (G_UNLIKELY (cur == NULL))
-    return NULL;
-
-  code = *sync_word;
-
-  while (cur < end) {
-    code <<= 8;
-
-    if (code == 0x00000100) {
-      /* Reset the sync word accumulator */
-      *sync_word = 0xffffffff;
-      return cur;
-    }
-
-    /* Add the next available byte to the collected sync word */
-    code |= *cur++;
-  }
-
-  *sync_word = code;
-  return NULL;
-}
-
 static void
 set_fps_from_code (MPEGSeqHdr * hdr, guint8 fps_code)
 {
@@ -150,157 +99,169 @@ set_par_from_dar (MPEGSeqHdr * hdr, guint8 asr_code)
   }
 }
 
-static gboolean
-mpeg_util_parse_extension_packet (MPEGSeqHdr * hdr, guint8 * data, guint8 * end)
+gboolean
+mpeg_util_parse_sequence_extension (MPEGSeqExtHdr * hdr, GstBuffer * buffer)
 {
-  guint8 ext_code;
+  GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buffer);;
 
-  if (G_UNLIKELY (data >= end))
-    return FALSE;               /* short extension packet */
+  /* skip sync word */
+  if (!gst_bit_reader_skip (&reader, 8 * 4))
+    return FALSE;
 
-  ext_code = read_bits (data, 0, 4);
+  /* skip extension code */
+  if (!gst_bit_reader_skip (&reader, 4))
+    return FALSE;
 
-  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;
+  /* skip profile and level escape bit */
+  if (!gst_bit_reader_skip (&reader, 1))
+    return FALSE;
 
-      if (G_UNLIKELY ((end - data) < 6))
-        /* need at least 10 bytes, minus 4 for the start code 000001b5 */
-        return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->profile, 3))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->level, 4))
+    return FALSE;
 
-      hdr->profile = read_bits (data, 7, 3);
+  /* progressive */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->progressive, 1))
+    return FALSE;
+
+  /* chroma format */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->chroma_format, 2))
+    return FALSE;
 
-      horiz_size_ext = read_bits (data + 1, 7, 2);
-      vert_size_ext = read_bits (data + 2, 1, 2);
+  /* resolution extension */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->horiz_size_ext, 2))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->vert_size_ext, 2))
+    return FALSE;
 
-      fps_n_ext = read_bits (data + 5, 1, 2);
-      fps_d_ext = read_bits (data + 5, 3, 5);
+  /* skip to framerate extension */
+  if (!gst_bit_reader_skip (&reader, 22))
+    return FALSE;
 
-      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;
-  }
+  /* framerate extension */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->fps_n_ext, 2))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->fps_d_ext, 2))
+    return FALSE;
 
   return TRUE;
 }
 
 gboolean
-mpeg_util_parse_sequence_hdr (MPEGSeqHdr * hdr, guint8 * data, guint8 * end)
+mpeg_util_parse_sequence_hdr (MPEGSeqHdr * hdr, GstBuffer * buffer)
 {
-  guint32 code;
-  guint8 dar_idx, fps_idx;
-  guint32 sync_word = 0xffffffff;
-  gboolean constrained_flag;
-  gboolean load_intra_flag;
-  gboolean load_non_intra_flag;
-  gint i;
+  GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buffer);
+  guint8 dar_idx, par_idx;
+  guint8 load_intra_flag, load_non_intra_flag;
 
-  if (G_UNLIKELY ((end - data) < 12))
-    return FALSE;               /* Too small to be a sequence header */
+  /* skip sync word */
+  if (!gst_bit_reader_skip (&reader, 8 * 4))
+    return FALSE;
 
-  code = GST_READ_UINT32_BE (data);
-  if (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_SEQUENCE)))
+  /* resolution */
+  if (!gst_bit_reader_get_bits_uint16 (&reader, &hdr->width, 12))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint16 (&reader, &hdr->height, 12))
     return FALSE;
 
-  /* Skip the sync word */
-  data += 4;
+  /* aspect ratio */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &dar_idx, 4))
+    return FALSE;
+  set_par_from_dar (hdr, dar_idx);
 
-  /* Parse the MPEG 1 bits */
-  hdr->mpeg_version = 1;
+  /* framerate */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &par_idx, 4))
+    return FALSE;
+  set_fps_from_code (hdr, par_idx);
 
-  code = GST_READ_UINT32_BE (data);
-  hdr->width = read_bits (data, 0, 12);
-  hdr->height = read_bits (data + 1, 4, 12);
+  /* bitrate */
+  if (!gst_bit_reader_get_bits_uint32 (&reader, &hdr->bitrate, 18))
+    return FALSE;
 
-  dar_idx = read_bits (data + 3, 0, 4);
-  set_par_from_dar (hdr, dar_idx);
-  fps_idx = read_bits (data + 3, 4, 4);
-  set_fps_from_code (hdr, fps_idx);
+  if (!gst_bit_reader_skip (&reader, 1))
+    return FALSE;
+
+  /* VBV buffer size */
+  if (!gst_bit_reader_get_bits_uint16 (&reader, &hdr->vbv_buffer, 10))
+    return FALSE;
 
-  constrained_flag = read_bits (data + 7, 5, 1);
+  /* constrained parameters flag */
+  if (!gst_bit_reader_get_bits_uint8 (&reader,
+          &hdr->constrained_parameters_flag, 1))
+    return FALSE;
 
-  load_intra_flag = read_bits (data + 7, 6, 1);
+  /* intra quantizer matrix */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &load_intra_flag, 1))
+    return FALSE;
   if (load_intra_flag) {
-    if (G_UNLIKELY ((end - data) < 64))
-      return FALSE;
+    gint i;
     for (i = 0; i < 64; i++) {
-      hdr->intra_quantizer_matrix[mpeg2_scan[i]] =
-          read_bits (data + 7 + i, 7, 8);
+      if (!gst_bit_reader_get_bits_uint8 (&reader,
+              &hdr->intra_quantizer_matrix[mpeg2_scan[i]], 8))
+        return FALSE;
     }
-    data += 64;
-
   } else
     memcpy (hdr->intra_quantizer_matrix, default_intra_quantizer_matrix, 64);
 
-  load_non_intra_flag = read_bits (data + 7, 7 + load_intra_flag, 1);
+  /* non intra quantizer matrix */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &load_non_intra_flag, 1))
+    return FALSE;
   if (load_non_intra_flag) {
-    if (G_UNLIKELY ((end - data) < 64))
-      return FALSE;
-    for (i = 0; i < 64; i++)
-      hdr->non_intra_quantizer_matrix[mpeg2_scan[i]] =
-          read_bits (data + 8 + i, 1 + load_intra_flag, 8);
-  } else
-    memset (hdr->non_intra_quantizer_matrix, 16, 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 (data >= end))
-      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))
+    gint i;
+    for (i = 0; i < 64; i++) {
+      if (!gst_bit_reader_get_bits_uint8 (&reader,
+              &hdr->non_intra_quantizer_matrix[mpeg2_scan[i]], 8))
         return FALSE;
-
-      hdr->mpeg_version = 2;
     }
-    data = mpeg_util_find_start_code (&sync_word, data, end);
-  }
+  } else
+    memset (hdr->non_intra_quantizer_matrix, 16, 64);
 
   return TRUE;
 }
 
 gboolean
-mpeg_util_parse_picture_hdr (MPEGPictureHdr * hdr, guint8 * data, guint8 * end)
+mpeg_util_parse_picture_hdr (MPEGPictureHdr * hdr, GstBuffer * buffer)
 {
-  guint32 code;
+  GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buffer);
 
-  if (G_UNLIKELY ((end - data) < 8))
-    return FALSE;               /* Packet too small */
+  /* skip sync word */
+  if (!gst_bit_reader_skip (&reader, 8 * 4))
+    return FALSE;
 
-  code = GST_READ_UINT32_BE (data);
-  if (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_PICTURE)))
+  /* temperal sequence number */
+  if (!gst_bit_reader_get_bits_uint16 (&reader, &hdr->tsn, 10))
     return FALSE;
 
-  /* Skip the sync word */
-  data += 4;
+  /* frame type */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->pic_type, 3))
+    return FALSE;
 
-  hdr->pic_type = (data[1] >> 3) & 0x07;
   if (hdr->pic_type == 0 || hdr->pic_type > 4)
     return FALSE;               /* Corrupted picture packet */
 
+  /* VBV delay */
+  if (!gst_bit_reader_get_bits_uint16 (&reader, &hdr->vbv_delay, 16))
+    return FALSE;
+
   if (hdr->pic_type == P_FRAME || hdr->pic_type == B_FRAME) {
-    if (G_UNLIKELY ((end - data) < 5))
-      return FALSE;             /* packet too small */
 
-    hdr->full_pel_forward_vector = read_bits (data + 3, 5, 1);
-    hdr->f_code[0][0] = hdr->f_code[0][1] = read_bits (data + 3, 6, 3);
+    if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->full_pel_forward_vector,
+            1))
+      return FALSE;
+
+    if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->f_code[0][0], 3))
+      return FALSE;
+    hdr->f_code[0][1] = hdr->f_code[0][0];
 
     if (hdr->pic_type == B_FRAME) {
-      hdr->full_pel_backward_vector = read_bits (data + 4, 1, 1);
-      hdr->f_code[1][0] = hdr->f_code[1][1] = read_bits (data + 4, 2, 3);
+      if (!gst_bit_reader_get_bits_uint8 (&reader,
+              &hdr->full_pel_backward_vector, 1))
+        return FALSE;
+
+      if (!gst_bit_reader_get_bits_uint8 (&reader, &hdr->f_code[1][0], 3))
+        return FALSE;
+      hdr->f_code[1][1] = hdr->f_code[1][0];
     } else
       hdr->full_pel_backward_vector = 0;
   } else {
@@ -312,104 +273,143 @@ mpeg_util_parse_picture_hdr (MPEGPictureHdr * hdr, guint8 * data, guint8 * end)
 }
 
 gboolean
-mpeg_util_parse_picture_coding_extension (MPEGPictureExt * ext, guint8 * data,
-    guint8 * end)
+mpeg_util_parse_picture_coding_extension (MPEGPictureExt * ext,
+    GstBuffer * buffer)
 {
-  guint32 code;
+  GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buffer);
 
-  if (G_UNLIKELY ((end - data) < 9))
-    return FALSE;               /* Packet too small */
+  /* skip sync word */
+  if (!gst_bit_reader_skip (&reader, 8 * 4))
+    return FALSE;
 
-  code = GST_READ_UINT32_BE (data);
+  /* skip extension code */
+  if (!gst_bit_reader_skip (&reader, 4))
+    return FALSE;
 
-  if (G_UNLIKELY (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_EXTENSION))))
+  /* f_code */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->f_code[0][0], 4))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->f_code[0][1], 4))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->f_code[1][0], 4))
+    return FALSE;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->f_code[1][1], 4))
     return FALSE;
 
-  /* Skip the sync word */
-  data += 4;
+  /* intra DC precision */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->intra_dc_precision, 2))
+    return FALSE;
 
-  ext->f_code[0][0] = read_bits (data, 4, 4);
-  ext->f_code[0][1] = read_bits (data + 1, 0, 4);
-  ext->f_code[1][0] = read_bits (data + 1, 4, 4);
-  ext->f_code[1][1] = read_bits (data + 2, 0, 4);
+  /* picture structure */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->picture_structure, 2))
+    return FALSE;
 
-  ext->intra_dc_precision = read_bits (data + 2, 4, 2);
-  ext->picture_structure = read_bits (data + 2, 6, 2);
-  ext->top_field_first = read_bits (data + 3, 0, 1);
-  ext->frame_pred_frame_dct = read_bits (data + 3, 1, 1);
-  ext->concealment_motion_vectors = read_bits (data + 3, 2, 1);
-  ext->q_scale_type = read_bits (data + 3, 3, 1);
-  ext->intra_vlc_format = read_bits (data + 3, 4, 1);
-  ext->alternate_scan = read_bits (data + 3, 5, 1);
+  /* top field first */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->top_field_first, 1))
+    return FALSE;
+
+  /* frame pred frame dct */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->frame_pred_frame_dct, 1))
+    return FALSE;
+
+  /* concealment motion vectors */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->concealment_motion_vectors,
+          1))
+    return FALSE;
+
+  /* q scale type */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->q_scale_type, 1))
+    return FALSE;
+
+  /* intra vlc format */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->intra_vlc_format, 1))
+    return FALSE;
+
+  /* alternate scan */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->alternate_scan, 1))
+    return FALSE;
+
+  /* repeat first field */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &ext->repeat_first_field, 1))
+    return FALSE;
 
   return TRUE;
 }
 
 gboolean
-mpeg_util_parse_picture_gop (MPEGPictureGOP * gop, guint8 * data, guint8 * end)
+mpeg_util_parse_gop (MPEGGop * gop, GstBuffer * buffer)
 {
-  guint32 code;
+  GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buffer);
 
-  if (G_UNLIKELY ((end - data) < 8))
-    return FALSE;               /* Packet too small */
+  /* skip sync word */
+  if (!gst_bit_reader_skip (&reader, 8 * 4))
+    return FALSE;
 
-  code = GST_READ_UINT32_BE (data);
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->drop_frame_flag, 1))
+    return FALSE;
 
-  if (G_UNLIKELY (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_GOP))))
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->hour, 5))
     return FALSE;
 
-  /* Skip the sync word */
-  data += 4;
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->minute, 6))
+    return FALSE;
+
+  /* skip unused bit */
+  if (!gst_bit_reader_skip (&reader, 1))
+    return FALSE;
 
-  gop->drop_frame_flag = read_bits (data, 0, 1);
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->second, 6))
+    return FALSE;
 
-  gop->hour = read_bits (data, 1, 5);
-  gop->minute = read_bits (data, 6, 6);
-  gop->second = read_bits (data + 1, 4, 6);
-  gop->frame = read_bits (data + 2, 3, 6);
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->frame, 6))
+    return FALSE;
+
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->closed_gop, 1))
+    return FALSE;
 
-  gop->closed_gop = read_bits (data + 3, 1, 1);
-  gop->broken_gop = read_bits (data + 3, 2, 1);
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &gop->broken_gop, 1))
+    return FALSE;
 
   return TRUE;
 }
 
 gboolean
-mpeg_util_parse_quant_matrix (MPEGQuantMatrix * qm, guint8 * data, guint8 * end)
+mpeg_util_parse_quant_matrix (MPEGQuantMatrix * qm, GstBuffer * buffer)
 {
-  guint32 code;
-  gboolean load_intra_flag, load_non_intra_flag;
-  gint i;
-
-  if (G_UNLIKELY ((end - data) < 5))
-    return FALSE;               /* Packet too small */
+  GstBitReader reader = GST_BIT_READER_INIT_FROM_BUFFER (buffer);
+  guint8 load_intra_flag, load_non_intra_flag;
 
-  code = GST_READ_UINT32_BE (data);
-
-  if (G_UNLIKELY (G_UNLIKELY (code != (0x00000100 | MPEG_PACKET_EXTENSION))))
+  /* skip sync word */
+  if (!gst_bit_reader_skip (&reader, 8 * 4))
     return FALSE;
 
-  /* Skip the sync word */
-  data += 4;
+  /* skip extension code */
+  if (!gst_bit_reader_skip (&reader, 4))
+    return FALSE;
 
-  load_intra_flag = read_bits (data, 4, 1);
+  /* intra quantizer matrix */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &load_intra_flag, 1))
+    return FALSE;
   if (load_intra_flag) {
-    if (G_UNLIKELY ((end - data) < 64))
-      return FALSE;
-    for (i = 0; i < 64; i++)
-      qm->intra_quantizer_matrix[mpeg2_scan[i]] = read_bits (data + i, 5, 8);
-
-    data += 64;
+    gint i;
+    for (i = 0; i < 64; i++) {
+      if (!gst_bit_reader_get_bits_uint8 (&reader,
+              &qm->intra_quantizer_matrix[mpeg2_scan[i]], 8))
+        return FALSE;
+    }
   } else
     memcpy (qm->intra_quantizer_matrix, default_intra_quantizer_matrix, 64);
 
-  load_non_intra_flag = read_bits (data, 5 + load_intra_flag, 1);
+  /* non intra quantizer matrix */
+  if (!gst_bit_reader_get_bits_uint8 (&reader, &load_non_intra_flag, 1))
+    return FALSE;
   if (load_non_intra_flag) {
-    if (G_UNLIKELY ((end - data) < 64))
-      return FALSE;
-    for (i = 0; i < 64; i++)
-      qm->non_intra_quantizer_matrix[mpeg2_scan[i]] =
-          read_bits (data + i, 6 + load_intra_flag, 8);
+    gint i;
+    for (i = 0; i < 64; i++) {
+      if (!gst_bit_reader_get_bits_uint8 (&reader,
+              &qm->non_intra_quantizer_matrix[mpeg2_scan[i]], 8))
+        return FALSE;
+    }
   } else
     memset (qm->non_intra_quantizer_matrix, 16, 64);
 
diff --git a/sys/vdpau/mpegutil.h b/sys/vdpau/mpegutil.h
index 43f34a59..4e5a656a 100644
--- a/sys/vdpau/mpegutil.h
+++ b/sys/vdpau/mpegutil.h
@@ -24,9 +24,10 @@
 #include <gst/gst.h>
 
 typedef struct MPEGSeqHdr MPEGSeqHdr;
+typedef struct MPEGSeqExtHdr MPEGSeqExtHdr;
 typedef struct MPEGPictureHdr MPEGPictureHdr;
 typedef struct MPEGPictureExt MPEGPictureExt;
-typedef struct MPEGPictureGOP MPEGPictureGOP;
+typedef struct MPEGGop MPEGGop;
 typedef struct MPEGQuantMatrix MPEGQuantMatrix;
 
 /* Packet ID codes for different packet types we
@@ -53,27 +54,45 @@ typedef struct MPEGQuantMatrix MPEGQuantMatrix;
 
 struct MPEGSeqHdr
 {
-  /* 0 for unknown, else 1 or 2 */
-  guint8 mpeg_version;
-
   /* Pixel-Aspect Ratio from DAR code via set_par_from_dar */
-  gint par_w, par_h;
+  guint par_w, par_h;
   /* Width and Height of the video */
-  gint width, height;
+  guint16 width, height;
   /* Framerate */
-  gint fps_n, fps_d;
+  guint fps_n, fps_d;
 
-  /* mpeg2 decoder profile */
-  gint profile;
+  guint32 bitrate;
+  guint16 vbv_buffer;
 
+  guint8 constrained_parameters_flag;
+  
   guint8 intra_quantizer_matrix[64];
   guint8 non_intra_quantizer_matrix[64];
 };
 
+struct MPEGSeqExtHdr
+{
+
+  /* mpeg2 decoder profile */
+  guint8 profile;
+  /* mpeg2 decoder level */
+  guint8 level;
+
+  guint8 progressive;
+  guint8 chroma_format;
+  
+  guint8 horiz_size_ext, vert_size_ext;
+
+  guint8 fps_n_ext, fps_d_ext;
+  
+};
+
 struct MPEGPictureHdr
 {
+  guint16 tsn;
   guint8 pic_type;
-
+  guint16 vbv_delay;
+  
   guint8 full_pel_forward_vector, full_pel_backward_vector;
 
   guint8 f_code[2][2];
@@ -91,9 +110,10 @@ struct MPEGPictureExt
   guint8 q_scale_type;
   guint8 intra_vlc_format;
   guint8 alternate_scan;
+  guint8 repeat_first_field;
 };
 
-struct MPEGPictureGOP
+struct MPEGGop
 {
   guint8 drop_frame_flag;
 
@@ -109,18 +129,19 @@ struct MPEGQuantMatrix
   guint8 non_intra_quantizer_matrix[64];
 };
 
-gboolean mpeg_util_parse_sequence_hdr (MPEGSeqHdr *hdr, 
-                                       guint8 *data, guint8 *end);
+gboolean mpeg_util_parse_sequence_hdr (MPEGSeqHdr *hdr, GstBuffer *buffer);
 
-gboolean mpeg_util_parse_picture_hdr (MPEGPictureHdr * hdr, guint8 * data, guint8 * end);
+gboolean mpeg_util_parse_sequence_extension (MPEGSeqExtHdr *hdr,
+    GstBuffer *buffer);
 
-gboolean mpeg_util_parse_picture_coding_extension (MPEGPictureExt *ext, guint8 *data, guint8 *end);
+gboolean mpeg_util_parse_picture_hdr (MPEGPictureHdr * hdr, GstBuffer *buffer);
 
-gboolean mpeg_util_parse_picture_gop (MPEGPictureGOP * gop, guint8 * data, guint8 * end);
+gboolean mpeg_util_parse_picture_coding_extension (MPEGPictureExt *ext,
+    GstBuffer *buffer);
 
-gboolean mpeg_util_parse_quant_matrix (MPEGQuantMatrix * qm, guint8 * data, guint8 * end);
+gboolean mpeg_util_parse_gop (MPEGGop * gop, GstBuffer *buffer);
 
-guint8 *mpeg_util_find_start_code (guint32 * sync_word, guint8 * cur, guint8 * end);
-guint32 read_bits (guint8 * buf, gint start_bit, gint n_bits);
+gboolean mpeg_util_parse_quant_matrix (MPEGQuantMatrix * qm, GstBuffer *buffer);
 
 #endif
+