gst/mpegpsmux/psmuxstream.c - mtk-gst-plugins-bad - Git at Google

 /* MPEG-PS muxer plugin for GStreamer
  * Copyright 2008 Lin YANG <oxcsnicho@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public
  * License along with this library; if not, write to the
  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 /*
  * Unless otherwise indicated, Source Code is licensed under MIT license.
  * See further explanation attached in License Statement (distributed in the file
  * LICENSE).
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
  * the Software without restriction, including without limitation the rights to
  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  * of the Software, and to permit persons to whom the Software is furnished to do
  * so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in all
  * copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <string.h>

 #include "psmuxcommon.h"
 #include "psmuxstream.h"
 #include "psmux.h"

 static guint8 psmux_stream_pes_header_length (PsMuxStream * stream);
 static void psmux_stream_write_pes_header (PsMuxStream * stream, guint8 * data);
 static void psmux_stream_find_pts_dts_within (PsMuxStream * stream, guint bound,
     gint64 * pts, gint64 * dts);

 /**
  * psmux_stream_new:
  * @pid: a PID
  * @stream_type: the stream type
  *
  * Create a new stream with type = @stream_type, assign stream id accordingly
  *
  * Returns: a new #PsMuxStream.
  */
 PsMuxStream *
 psmux_stream_new (PsMux * mux, PsMuxStreamType stream_type)
 {
   PsMuxStream *stream = g_slice_new0 (PsMuxStream);
   PsMuxStreamIdInfo *info = &(mux->id_info);

   stream->stream_type = stream_type;
   stream->is_audio_stream = FALSE;
   stream->is_video_stream = FALSE;
   stream->stream_id = 0;
   stream->max_buffer_size = 0;

   switch (stream_type) {
       /* MPEG AUDIO */
     case PSMUX_ST_AUDIO_MPEG1:
     case PSMUX_ST_AUDIO_MPEG2:
       stream->max_buffer_size = 2484;   /* ISO/IEC 13818 2.5.2.4 */
     case PSMUX_ST_AUDIO_AAC:
       if (info->id_mpga > PSMUX_STREAM_ID_MPGA_MAX)
         break;
       stream->stream_id = info->id_mpga++;
       stream->stream_id_ext = 0;
       stream->is_audio_stream = TRUE;
       break;
       /* MPEG VIDEO */
     case PSMUX_ST_VIDEO_MPEG1:
     case PSMUX_ST_VIDEO_MPEG2:
     case PSMUX_ST_VIDEO_MPEG4:
     case PSMUX_ST_VIDEO_H264:
       if (info->id_mpgv > PSMUX_STREAM_ID_MPGV_MAX)
         break;
       stream->stream_id = info->id_mpgv++;
       stream->stream_id_ext = 0;
       stream->is_video_stream = TRUE;
       break;
       /* AC3 / A52 */
     case PSMUX_ST_PS_AUDIO_AC3:
       if (info->id_ac3 > PSMUX_STREAM_ID_AC3_MAX)
         break;
       stream->stream_id = PSMUX_PRIVATE_STREAM_1;
       stream->stream_id_ext = info->id_ac3++;
       stream->is_audio_stream = TRUE;
       /* AC3 requires data alignment */
       stream->pi.flags |= PSMUX_PACKET_FLAG_PES_DATA_ALIGN;
       break;
       /* TODO: SPU missing */
 #if 0
     case spu:
       if (info->id_spu > PSMUX_STREAM_ID_SPU_MAX)
         break;
       return info->id_spu++;
 #endif
       /* DTS */
     case PSMUX_ST_PS_AUDIO_DTS:
       if (info->id_dts > PSMUX_STREAM_ID_DTS_MAX)
         break;
       stream->stream_id = PSMUX_PRIVATE_STREAM_1;
       stream->stream_id_ext = info->id_dts++;
       stream->is_audio_stream = TRUE;
       break;
       /* LPCM */
     case PSMUX_ST_PS_AUDIO_LPCM:
       if (info->id_lpcm > PSMUX_STREAM_ID_LPCM_MAX)
         break;
       stream->stream_id = PSMUX_PRIVATE_STREAM_1;
       stream->stream_id_ext = info->id_lpcm++;
       stream->is_audio_stream = TRUE;
       break;
     case PSMUX_ST_VIDEO_DIRAC:
       if (info->id_dirac > PSMUX_STREAM_ID_DIRAC_MAX)
         break;
       stream->stream_id = PSMUX_EXTENDED_STREAM;
       stream->stream_id_ext = info->id_dirac++;
       stream->is_video_stream = TRUE;
       break;
     default:
       g_critical ("Stream type 0x%0x not yet implemented", stream_type);
       break;
   }

   if (stream->stream_id == 0) {
     g_critical ("Number of elementary streams of type %04x exceeds maximum",
         stream->stream_type);
     g_slice_free (PsMuxStream, stream);
     return NULL;
   }

   /* XXX: Are private streams also using stream_id_ext? */
   if (stream->stream_id == PSMUX_EXTENDED_STREAM)
     stream->pi.flags |= PSMUX_PACKET_FLAG_PES_EXT_STREAMID;

   /* Are these useful at all? */
   if (stream->stream_id == PSMUX_PROGRAM_STREAM_MAP ||
       stream->stream_id == PSMUX_PADDING_STREAM ||
       stream->stream_id == PSMUX_PRIVATE_STREAM_2 ||
       stream->stream_id == PSMUX_ECM ||
       stream->stream_id == PSMUX_EMM ||
       stream->stream_id == PSMUX_PROGRAM_STREAM_DIRECTORY ||
       stream->stream_id == PSMUX_DSMCC_STREAM ||
       stream->stream_id == PSMUX_ITU_T_H222_1_TYPE_E)
     stream->pi.flags &= ~PSMUX_PACKET_FLAG_PES_FULL_HEADER;
   else
     stream->pi.flags |= PSMUX_PACKET_FLAG_PES_FULL_HEADER;

   stream->buffers = NULL;
   stream->bytes_avail = 0;
   stream->cur_buffer = NULL;
   stream->cur_buffer_consumed = 0;

   stream->cur_pes_payload_size = 0;

   stream->pts = -1;
   stream->dts = -1;
   stream->last_pts = -1;

   /* These fields are set by gstreamer */
   stream->audio_sampling = 0;
   stream->audio_channels = 0;
   stream->audio_bitrate = 0;

   if (stream->max_buffer_size == 0) {
     /* XXX: VLC'S VALUE. Better default? */
     if (stream->is_video_stream)
       stream->max_buffer_size = 400 * 1024;
     else if (stream->is_audio_stream)
       stream->max_buffer_size = 4 * 1024;
     else
       g_assert_not_reached ();
   }

   return stream;
 }

 /**
  * psmux_stream_free:
  * @stream: a #PsMuxStream
  *
  * Free the resources of @stream.
  */
 void
 psmux_stream_free (PsMuxStream * stream)
 {
   g_return_if_fail (stream != NULL);

   if (psmux_stream_bytes_in_buffer (stream)) {
     g_warning ("Freeing stream with data not yet processed");
   }
   g_slice_free (PsMuxStream, stream);
 }

 /* Advance the current packet stream position by len bytes.
  * Mustn't consume more than available in the current packet */
 static void
 psmux_stream_consume (PsMuxStream * stream, guint len)
 {
   g_assert (stream->cur_buffer != NULL);
   g_assert (len <= stream->cur_buffer->map.size - stream->cur_buffer_consumed);

   stream->cur_buffer_consumed += len;
   stream->bytes_avail -= len;

   if (stream->cur_buffer_consumed == 0)
     return;

   if (stream->cur_buffer->pts != -1)
     stream->last_pts = stream->cur_buffer->pts;

   if (stream->cur_buffer_consumed == stream->cur_buffer->map.size) {
     /* Current packet is completed, move along */
     stream->buffers = g_list_delete_link (stream->buffers, stream->buffers);

     gst_buffer_unmap (stream->cur_buffer->buf, &stream->cur_buffer->map);
     gst_buffer_unref (stream->cur_buffer->buf);
     g_slice_free (PsMuxStreamBuffer, stream->cur_buffer);
     stream->cur_buffer = NULL;
   }
 }


 /**
  * psmux_stream_bytes_in_buffer:
  * @stream: a #PsMuxStream
  *
  * Calculate how much bytes are in the buffer.
  *
  * Returns: The number of bytes in the buffer.
  */
 gint
 psmux_stream_bytes_in_buffer (PsMuxStream * stream)
 {
   g_return_val_if_fail (stream != NULL, 0);

   return stream->bytes_avail;
 }

 /**
  * psmux_stream_get_data:
  * @stream: a #PsMuxStream
  * @buf: a buffer to hold the result
  * @len: the length of @buf
  *
  * Write a PES packet to @buf, up to @len bytes
  *
  * Returns: number of bytes having been written, 0 if error
  */
 guint
 psmux_stream_get_data (PsMuxStream * stream, guint8 * buf, guint len)
 {
   guint8 pes_hdr_length;
   guint w;

   g_return_val_if_fail (stream != NULL, FALSE);
   g_return_val_if_fail (buf != NULL, FALSE);
   g_return_val_if_fail (len >= PSMUX_PES_MAX_HDR_LEN, FALSE);

   stream->cur_pes_payload_size =
       MIN (psmux_stream_bytes_in_buffer (stream), len - PSMUX_PES_MAX_HDR_LEN);
   /* Note that we cannot make a better estimation of the header length for the
    * time being; because the header length is dependent on whether we can find a
    * timestamp in the upcomming buffers, which in turn depends on
    * cur_pes_payload_size, which is exactly what we want to decide.
    */

   psmux_stream_find_pts_dts_within (stream, stream->cur_pes_payload_size,
       &stream->pts, &stream->dts);

   /* clear pts/dts flag */
   stream->pi.flags &= ~(PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS |
       PSMUX_PACKET_FLAG_PES_WRITE_PTS);
   /* update pts/dts flag */
   if (stream->pts != -1 && stream->dts != -1)
     stream->pi.flags |= PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS;
   else {
     if (stream->pts != -1)
       stream->pi.flags |= PSMUX_PACKET_FLAG_PES_WRITE_PTS;
   }

   pes_hdr_length = psmux_stream_pes_header_length (stream);

   /* write pes header */
   GST_LOG ("Writing PES header of length %u and payload %d",
       pes_hdr_length, stream->cur_pes_payload_size);
   psmux_stream_write_pes_header (stream, buf);

   buf += pes_hdr_length;
   w = stream->cur_pes_payload_size;     /* number of bytes of payload to write */

   while (w > 0) {
     guint32 avail;
     guint8 *cur;

     if (stream->cur_buffer == NULL) {
       /* Start next packet */
       if (stream->buffers == NULL)
         return FALSE;
       stream->cur_buffer = (PsMuxStreamBuffer *) (stream->buffers->data);
       stream->cur_buffer_consumed = 0;
     }

     /* Take as much as we can from the current buffer */
     avail = stream->cur_buffer->map.size - stream->cur_buffer_consumed;
     cur = stream->cur_buffer->map.data + stream->cur_buffer_consumed;
     if (avail < w) {
       memcpy (buf, cur, avail);
       psmux_stream_consume (stream, avail);

       buf += avail;
       w -= avail;
     } else {
       memcpy (buf, cur, w);
       psmux_stream_consume (stream, w);

       w = 0;
     }
   }

   return pes_hdr_length + stream->cur_pes_payload_size;
 }

 static guint8
 psmux_stream_pes_header_length (PsMuxStream * stream)
 {
   guint8 packet_len;

   /* Calculate the length of the header for this stream */

   /* start_code prefix + stream_id + pes_packet_length = 6 bytes */
   packet_len = 6;

   if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_FULL_HEADER) {
     /* For a PES 'full header' we have at least 3 more bytes,
      * and then more based on flags */
     packet_len += 3;
     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS) {
       packet_len += 10;
     } else if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS) {
       packet_len += 5;
     }
     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_EXT_STREAMID) {
       /* Need basic extension flags (1 byte), plus 2 more bytes for the
        * length + extended stream id */
       packet_len += 3;
     }
   }

   return packet_len;
 }

 /* Find a PTS/DTS to write into the pes header within the next bound bytes
  * of the data */
 static void
 psmux_stream_find_pts_dts_within (PsMuxStream * stream, guint bound,
     gint64 * pts, gint64 * dts)
 {
   /* 1. When there are at least one buffer then output the first buffer with
    * pts/dts
    * 2. If the bound is too small to include even one buffer, output the pts/dts
    * of that buffer.
    */
   GList *cur;

   *pts = -1;
   *dts = -1;

   for (cur = g_list_first (stream->buffers); cur != NULL;
       cur = g_list_next (cur)) {
     PsMuxStreamBuffer *curbuf = cur->data;

     /* FIXME: This isn't quite correct - if the 'bound' is within this
      * buffer, we don't know if the timestamp is before or after the split
      * so we shouldn't return it */
     if (bound <= curbuf->map.size) {
       *pts = curbuf->pts;
       *dts = curbuf->dts;
       return;
     }

     /* Have we found a buffer with pts/dts set? */
     if (curbuf->pts != -1 || curbuf->dts != -1) {
       *pts = curbuf->pts;
       *dts = curbuf->dts;
       return;
     }

     bound -= curbuf->map.size;
   }
 }

 static void
 psmux_stream_write_pes_header (PsMuxStream * stream, guint8 * data)
 {
   guint16 length_to_write;
   guint8 hdr_len = psmux_stream_pes_header_length (stream);

   /* start_code prefix + stream_id + pes_packet_length = 6 bytes */
   data[0] = 0x00;
   data[1] = 0x00;
   data[2] = 0x01;
   data[3] = stream->stream_id;
   data += 4;

   length_to_write = hdr_len - 6 + stream->cur_pes_payload_size;

   psmux_put16 (&data, length_to_write);

   if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_FULL_HEADER) {
     guint8 flags = 0;

     /* Not scrambled, original, not-copyrighted, data_alignment specified by flag */
     flags = 0x81;
     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_DATA_ALIGN)
       flags |= 0x04;            /* Enable data_alignment_indicator */
     *data++ = flags;

     /* Flags */
     flags = 0;
     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS)
       flags |= 0xC0;
     else if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS)
       flags |= 0x80;
     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_EXT_STREAMID)
       flags |= 0x01;            /* Enable PES_extension_flag */
     *data++ = flags;

     /* Header length is the total pes length,
      * minus the 9 bytes of start codes, flags + hdr_len */
     g_return_if_fail (hdr_len >= 9);
     *data++ = (hdr_len - 9);

     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS) {
       psmux_put_ts (&data, 0x3, stream->pts);
       psmux_put_ts (&data, 0x1, stream->dts);
     } else if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS) {
       psmux_put_ts (&data, 0x2, stream->pts);
     }

     if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_EXT_STREAMID) {
       guint8 ext_len;

       flags = 0x0f;             /* preceeding flags all 0 | (reserved bits) | PES_extension_flag_2 */
       *data++ = flags;

       ext_len = 1;              /* Only writing 1 byte into the extended fields */
       *data++ = 0x80 | ext_len; /* marker | PES_extension_field_length */
       *data++ = 0x80 | stream->stream_id_ext;   /* stream_id_extension_flag | extended_stream_id */
     }
   }
 }

 /**
  * psmux_stream_add_data:
  * @stream: a #PsMuxStream
  * @buffer: (transfer full): buffer with data to add
  * @pts: PTS of access unit in @data
  * @dts: DTS of access unit in @data
  *
  * Submit @len bytes of @data into @stream. @pts and @dts can be set to the
  * timestamp (against a 90Hz clock) of the first access unit in @data. A
  * timestamp of -1 for @pts or @dts means unknown.
  *
  * This function takes ownership of @buffer.
  */
 void
 psmux_stream_add_data (PsMuxStream * stream, GstBuffer * buffer,
     gint64 pts, gint64 dts, gboolean keyunit)
 {
   PsMuxStreamBuffer *packet;

   g_return_if_fail (stream != NULL);

   packet = g_slice_new (PsMuxStreamBuffer);
   packet->buf = buffer;

   if (!gst_buffer_map (packet->buf, &packet->map, GST_MAP_READ)) {
     GST_ERROR ("Failed to map buffer for reading");
     gst_buffer_unref (packet->buf);
     g_slice_free (PsMuxStreamBuffer, packet);
     return;
   }

   packet->keyunit = keyunit;
   packet->pts = pts;
   packet->dts = dts;

   if (stream->bytes_avail == 0)
     stream->last_pts = pts;

   stream->bytes_avail += packet->map.size;
   /* FIXME: perhaps use GstQueueArray instead? */
   stream->buffers = g_list_append (stream->buffers, packet);

 }

 /**
  * psmux_stream_get_es_descrs:
  * @stream: a #PsMuxStream
  * @buf: a buffer to hold the ES descriptor
  * @len: the length used in @buf
  *
  * Write an Elementary Stream Descriptor for @stream into @buf. the number of
  * bytes consumed in @buf will be updated in @len.
  *
  * @buf and @len must be at least #PSMUX_MIN_ES_DESC_LEN.
  */
 void
 psmux_stream_get_es_descrs (PsMuxStream * stream, guint8 * buf, guint16 * len)
 {
   guint8 *pos;

   g_return_if_fail (stream != NULL);

   if (buf == NULL) {
     if (len != NULL)
       *len = 0;
     return;
   }

   /* Based on the stream type, write out any descriptors to go in the
    * PMT ES_info field */
   pos = buf;

   /* tag (registration_descriptor), length, format_identifier */
   switch (stream->stream_type) {
     case PSMUX_ST_AUDIO_AAC:
       /* FIXME */
       break;
     case PSMUX_ST_VIDEO_MPEG4:
       /* FIXME */
       break;
     case PSMUX_ST_VIDEO_H264:
       *pos++ = 0x05;
       *pos++ = 8;
       *pos++ = 0x48;            /* 'H' */
       *pos++ = 0x44;            /* 'D' */
       *pos++ = 0x4D;            /* 'M' */
       *pos++ = 0x56;            /* 'V' */
       /* FIXME : Not sure about this additional_identification_info */
       *pos++ = 0xFF;
       *pos++ = 0x1B;
       *pos++ = 0x44;
       *pos++ = 0x3F;
       break;
     case PSMUX_ST_VIDEO_DIRAC:
       *pos++ = 0x05;
       *pos++ = 4;
       *pos++ = 0x64;            /* 'd' */
       *pos++ = 0x72;            /* 'r' */
       *pos++ = 0x61;            /* 'a' */
       *pos++ = 0x63;            /* 'c' */
       break;
     case PSMUX_ST_PS_AUDIO_AC3:
     {
       *pos++ = 0x05;
       *pos++ = 4;
       *pos++ = 0x41;            /* 'A' */
       *pos++ = 0x43;            /* 'C' */
       *pos++ = 0x2D;            /* '-' */
       *pos++ = 0x33;            /* '3' */

       /* audio_stream_descriptor () | ATSC A/52-2001 Annex A
        *
        * descriptor_tag       8 uimsbf
        * descriptor_length    8 uimsbf
        * sample_rate_code     3 bslbf
        * bsid                 5 bslbf
        * bit_rate_code        6 bslbf
        * surround_mode        2 bslbf
        * bsmod                3 bslbf
        * num_channels         4 bslbf
        * full_svc             1 bslbf
        * langcod              8 bslbf
        * [...]
        */
       *pos++ = 0x81;
       *pos++ = 0x04;

       /* 3 bits sample_rate_code, 5 bits hardcoded bsid (default ver 8) */
       switch (stream->audio_sampling) {
         case 48000:
           *pos++ = 0x08;
           break;
         case 44100:
           *pos++ = 0x28;
           break;
         case 32000:
           *pos++ = 0x48;
           break;
         default:
           *pos++ = 0xE8;
           break;                /* 48, 44.1 or 32 Khz */
       }

       /* 1 bit bit_rate_limit, 5 bits bit_rate_code, 2 bits suround_mode */
       switch (stream->audio_bitrate) {
         case 32:
           *pos++ = 0x00 << 2;
           break;
         case 40:
           *pos++ = 0x01 << 2;
           break;
         case 48:
           *pos++ = 0x02 << 2;
           break;
         case 56:
           *pos++ = 0x03 << 2;
           break;
         case 64:
           *pos++ = 0x04 << 2;
           break;
         case 80:
           *pos++ = 0x05 << 2;
           break;
         case 96:
           *pos++ = 0x06 << 2;
           break;
         case 112:
           *pos++ = 0x07 << 2;
           break;
         case 128:
           *pos++ = 0x08 << 2;
           break;
         case 160:
           *pos++ = 0x09 << 2;
           break;
         case 192:
           *pos++ = 0x0A << 2;
           break;
         case 224:
           *pos++ = 0x0B << 2;
           break;
         case 256:
           *pos++ = 0x0C << 2;
           break;
         case 320:
           *pos++ = 0x0D << 2;
           break;
         case 384:
           *pos++ = 0x0E << 2;
           break;
         case 448:
           *pos++ = 0x0F << 2;
           break;
         case 512:
           *pos++ = 0x10 << 2;
           break;
         case 576:
           *pos++ = 0x11 << 2;
           break;
         case 640:
           *pos++ = 0x12 << 2;
           break;
         default:
           *pos++ = 0x32 << 2;
           break;                /* 640 Kb/s upper limit */
       }

       /* 3 bits bsmod, 4 bits num_channels, 1 bit full_svc */
       switch (stream->audio_channels) {
         case 1:
           *pos++ = 0x01 << 1;
           break;                /* 1/0 */
         case 2:
           *pos++ = 0x02 << 1;
           break;                /* 2/0 */
         case 3:
           *pos++ = 0x0A << 1;
           break;                /* <= 3 */
         case 4:
           *pos++ = 0x0B << 1;
           break;                /* <= 4 */
         case 5:
           *pos++ = 0x0C << 1;
           break;                /* <= 5 */
         case 6:
         default:
           *pos++ = 0x0D << 1;
           break;                /* <= 6 */
       }

       *pos++ = 0x00;

       break;
     }
     case PSMUX_ST_PS_AUDIO_DTS:
       /* FIXME */
       break;
     case PSMUX_ST_PS_AUDIO_LPCM:
       /* FIXME */
       break;
     default:
       break;
   }

   if (len)
     *len = (pos - buf);
 }

 /**
  * psmux_stream_get_pts:
  * @stream: a #PsMuxStream
  *
  * Return the PTS of the last buffer that has had bytes written and
  * which _had_ a PTS in @stream.
  *
  * Returns: the PTS of the last buffer in @stream.
  */
 guint64
 psmux_stream_get_pts (PsMuxStream * stream)
 {
   g_return_val_if_fail (stream != NULL, -1);

   return stream->last_pts;
 }
	/* MPEG-PS muxer plugin for GStreamer
	* Copyright 2008 Lin YANG <oxcsnicho@gmail.com>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public
	* License along with this library; if not, write to the
	* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/
	/*
	* Unless otherwise indicated, Source Code is licensed under MIT license.
	* See further explanation attached in License Statement (distributed in the file
	* LICENSE).
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy of
	* this software and associated documentation files (the "Software"), to deal in
	* the Software without restriction, including without limitation the rights to
	* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
	* of the Software, and to permit persons to whom the Software is furnished to do
	* so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in all
	* copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <string.h>

	#include "psmuxcommon.h"
	#include "psmuxstream.h"
	#include "psmux.h"

	static guint8 psmux_stream_pes_header_length (PsMuxStream * stream);
	static void psmux_stream_write_pes_header (PsMuxStream * stream, guint8 * data);
	static void psmux_stream_find_pts_dts_within (PsMuxStream * stream, guint bound,
	gint64 * pts, gint64 * dts);

	/**
	* psmux_stream_new:
	* @pid: a PID
	* @stream_type: the stream type
	*
	* Create a new stream with type = @stream_type, assign stream id accordingly
	*
	* Returns: a new #PsMuxStream.
	*/
	PsMuxStream *
	psmux_stream_new (PsMux * mux, PsMuxStreamType stream_type)
	{
	PsMuxStream *stream = g_slice_new0 (PsMuxStream);
	PsMuxStreamIdInfo *info = &(mux->id_info);

	stream->stream_type = stream_type;
	stream->is_audio_stream = FALSE;
	stream->is_video_stream = FALSE;
	stream->stream_id = 0;
	stream->max_buffer_size = 0;

	switch (stream_type) {
	/* MPEG AUDIO */
	case PSMUX_ST_AUDIO_MPEG1:
	case PSMUX_ST_AUDIO_MPEG2:
	stream->max_buffer_size = 2484; /* ISO/IEC 13818 2.5.2.4 */
	case PSMUX_ST_AUDIO_AAC:
	if (info->id_mpga > PSMUX_STREAM_ID_MPGA_MAX)
	break;
	stream->stream_id = info->id_mpga++;
	stream->stream_id_ext = 0;
	stream->is_audio_stream = TRUE;
	break;
	/* MPEG VIDEO */
	case PSMUX_ST_VIDEO_MPEG1:
	case PSMUX_ST_VIDEO_MPEG2:
	case PSMUX_ST_VIDEO_MPEG4:
	case PSMUX_ST_VIDEO_H264:
	if (info->id_mpgv > PSMUX_STREAM_ID_MPGV_MAX)
	break;
	stream->stream_id = info->id_mpgv++;
	stream->stream_id_ext = 0;
	stream->is_video_stream = TRUE;
	break;
	/* AC3 / A52 */
	case PSMUX_ST_PS_AUDIO_AC3:
	if (info->id_ac3 > PSMUX_STREAM_ID_AC3_MAX)
	break;
	stream->stream_id = PSMUX_PRIVATE_STREAM_1;
	stream->stream_id_ext = info->id_ac3++;
	stream->is_audio_stream = TRUE;
	/* AC3 requires data alignment */
	stream->pi.flags \|= PSMUX_PACKET_FLAG_PES_DATA_ALIGN;
	break;
	/* TODO: SPU missing */
	#if 0
	case spu:
	if (info->id_spu > PSMUX_STREAM_ID_SPU_MAX)
	break;
	return info->id_spu++;
	#endif
	/* DTS */
	case PSMUX_ST_PS_AUDIO_DTS:
	if (info->id_dts > PSMUX_STREAM_ID_DTS_MAX)
	break;
	stream->stream_id = PSMUX_PRIVATE_STREAM_1;
	stream->stream_id_ext = info->id_dts++;
	stream->is_audio_stream = TRUE;
	break;
	/* LPCM */
	case PSMUX_ST_PS_AUDIO_LPCM:
	if (info->id_lpcm > PSMUX_STREAM_ID_LPCM_MAX)
	break;
	stream->stream_id = PSMUX_PRIVATE_STREAM_1;
	stream->stream_id_ext = info->id_lpcm++;
	stream->is_audio_stream = TRUE;
	break;
	case PSMUX_ST_VIDEO_DIRAC:
	if (info->id_dirac > PSMUX_STREAM_ID_DIRAC_MAX)
	break;
	stream->stream_id = PSMUX_EXTENDED_STREAM;
	stream->stream_id_ext = info->id_dirac++;
	stream->is_video_stream = TRUE;
	break;
	default:
	g_critical ("Stream type 0x%0x not yet implemented", stream_type);
	break;
	}

	if (stream->stream_id == 0) {
	g_critical ("Number of elementary streams of type %04x exceeds maximum",
	stream->stream_type);
	g_slice_free (PsMuxStream, stream);
	return NULL;
	}

	/* XXX: Are private streams also using stream_id_ext? */
	if (stream->stream_id == PSMUX_EXTENDED_STREAM)
	stream->pi.flags \|= PSMUX_PACKET_FLAG_PES_EXT_STREAMID;

	/* Are these useful at all? */
	if (stream->stream_id == PSMUX_PROGRAM_STREAM_MAP \|\|
	stream->stream_id == PSMUX_PADDING_STREAM \|\|
	stream->stream_id == PSMUX_PRIVATE_STREAM_2 \|\|
	stream->stream_id == PSMUX_ECM \|\|
	stream->stream_id == PSMUX_EMM \|\|
	stream->stream_id == PSMUX_PROGRAM_STREAM_DIRECTORY \|\|
	stream->stream_id == PSMUX_DSMCC_STREAM \|\|
	stream->stream_id == PSMUX_ITU_T_H222_1_TYPE_E)
	stream->pi.flags &= ~PSMUX_PACKET_FLAG_PES_FULL_HEADER;
	else
	stream->pi.flags \|= PSMUX_PACKET_FLAG_PES_FULL_HEADER;

	stream->buffers = NULL;
	stream->bytes_avail = 0;
	stream->cur_buffer = NULL;
	stream->cur_buffer_consumed = 0;

	stream->cur_pes_payload_size = 0;

	stream->pts = -1;
	stream->dts = -1;
	stream->last_pts = -1;

	/* These fields are set by gstreamer */
	stream->audio_sampling = 0;
	stream->audio_channels = 0;
	stream->audio_bitrate = 0;

	if (stream->max_buffer_size == 0) {
	/* XXX: VLC'S VALUE. Better default? */
	if (stream->is_video_stream)
	stream->max_buffer_size = 400 * 1024;
	else if (stream->is_audio_stream)
	stream->max_buffer_size = 4 * 1024;
	else
	g_assert_not_reached ();
	}

	return stream;
	}

	/**
	* psmux_stream_free:
	* @stream: a #PsMuxStream
	*
	* Free the resources of @stream.
	*/
	void
	psmux_stream_free (PsMuxStream * stream)
	{
	g_return_if_fail (stream != NULL);

	if (psmux_stream_bytes_in_buffer (stream)) {
	g_warning ("Freeing stream with data not yet processed");
	}
	g_slice_free (PsMuxStream, stream);
	}

	/* Advance the current packet stream position by len bytes.
	* Mustn't consume more than available in the current packet */
	static void
	psmux_stream_consume (PsMuxStream * stream, guint len)
	{
	g_assert (stream->cur_buffer != NULL);
	g_assert (len <= stream->cur_buffer->map.size - stream->cur_buffer_consumed);

	stream->cur_buffer_consumed += len;
	stream->bytes_avail -= len;

	if (stream->cur_buffer_consumed == 0)
	return;

	if (stream->cur_buffer->pts != -1)
	stream->last_pts = stream->cur_buffer->pts;

	if (stream->cur_buffer_consumed == stream->cur_buffer->map.size) {
	/* Current packet is completed, move along */
	stream->buffers = g_list_delete_link (stream->buffers, stream->buffers);

	gst_buffer_unmap (stream->cur_buffer->buf, &stream->cur_buffer->map);
	gst_buffer_unref (stream->cur_buffer->buf);
	g_slice_free (PsMuxStreamBuffer, stream->cur_buffer);
	stream->cur_buffer = NULL;
	}
	}


	/**
	* psmux_stream_bytes_in_buffer:
	* @stream: a #PsMuxStream
	*
	* Calculate how much bytes are in the buffer.
	*
	* Returns: The number of bytes in the buffer.
	*/
	gint
	psmux_stream_bytes_in_buffer (PsMuxStream * stream)
	{
	g_return_val_if_fail (stream != NULL, 0);

	return stream->bytes_avail;
	}

	/**
	* psmux_stream_get_data:
	* @stream: a #PsMuxStream
	* @buf: a buffer to hold the result
	* @len: the length of @buf
	*
	* Write a PES packet to @buf, up to @len bytes
	*
	* Returns: number of bytes having been written, 0 if error
	*/
	guint
	psmux_stream_get_data (PsMuxStream * stream, guint8 * buf, guint len)
	{
	guint8 pes_hdr_length;
	guint w;

	g_return_val_if_fail (stream != NULL, FALSE);
	g_return_val_if_fail (buf != NULL, FALSE);
	g_return_val_if_fail (len >= PSMUX_PES_MAX_HDR_LEN, FALSE);

	stream->cur_pes_payload_size =
	MIN (psmux_stream_bytes_in_buffer (stream), len - PSMUX_PES_MAX_HDR_LEN);
	/* Note that we cannot make a better estimation of the header length for the
	* time being; because the header length is dependent on whether we can find a
	* timestamp in the upcomming buffers, which in turn depends on
	* cur_pes_payload_size, which is exactly what we want to decide.
	*/

	psmux_stream_find_pts_dts_within (stream, stream->cur_pes_payload_size,
	&stream->pts, &stream->dts);

	/* clear pts/dts flag */
	stream->pi.flags &= ~(PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS \|
	PSMUX_PACKET_FLAG_PES_WRITE_PTS);
	/* update pts/dts flag */
	if (stream->pts != -1 && stream->dts != -1)
	stream->pi.flags \|= PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS;
	else {
	if (stream->pts != -1)
	stream->pi.flags \|= PSMUX_PACKET_FLAG_PES_WRITE_PTS;
	}

	pes_hdr_length = psmux_stream_pes_header_length (stream);

	/* write pes header */
	GST_LOG ("Writing PES header of length %u and payload %d",
	pes_hdr_length, stream->cur_pes_payload_size);
	psmux_stream_write_pes_header (stream, buf);

	buf += pes_hdr_length;
	w = stream->cur_pes_payload_size; /* number of bytes of payload to write */

	while (w > 0) {
	guint32 avail;
	guint8 *cur;

	if (stream->cur_buffer == NULL) {
	/* Start next packet */
	if (stream->buffers == NULL)
	return FALSE;
	stream->cur_buffer = (PsMuxStreamBuffer *) (stream->buffers->data);
	stream->cur_buffer_consumed = 0;
	}

	/* Take as much as we can from the current buffer */
	avail = stream->cur_buffer->map.size - stream->cur_buffer_consumed;
	cur = stream->cur_buffer->map.data + stream->cur_buffer_consumed;
	if (avail < w) {
	memcpy (buf, cur, avail);
	psmux_stream_consume (stream, avail);

	buf += avail;
	w -= avail;
	} else {
	memcpy (buf, cur, w);
	psmux_stream_consume (stream, w);

	w = 0;
	}
	}

	return pes_hdr_length + stream->cur_pes_payload_size;
	}

	static guint8
	psmux_stream_pes_header_length (PsMuxStream * stream)
	{
	guint8 packet_len;

	/* Calculate the length of the header for this stream */

	/* start_code prefix + stream_id + pes_packet_length = 6 bytes */
	packet_len = 6;

	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_FULL_HEADER) {
	/* For a PES 'full header' we have at least 3 more bytes,
	* and then more based on flags */
	packet_len += 3;
	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS) {
	packet_len += 10;
	} else if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS) {
	packet_len += 5;
	}
	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_EXT_STREAMID) {
	/* Need basic extension flags (1 byte), plus 2 more bytes for the
	* length + extended stream id */
	packet_len += 3;
	}
	}

	return packet_len;
	}

	/* Find a PTS/DTS to write into the pes header within the next bound bytes
	* of the data */
	static void
	psmux_stream_find_pts_dts_within (PsMuxStream * stream, guint bound,
	gint64 * pts, gint64 * dts)
	{
	/* 1. When there are at least one buffer then output the first buffer with
	* pts/dts
	* 2. If the bound is too small to include even one buffer, output the pts/dts
	* of that buffer.
	*/
	GList *cur;

	*pts = -1;
	*dts = -1;

	for (cur = g_list_first (stream->buffers); cur != NULL;
	cur = g_list_next (cur)) {
	PsMuxStreamBuffer *curbuf = cur->data;

	/* FIXME: This isn't quite correct - if the 'bound' is within this
	* buffer, we don't know if the timestamp is before or after the split
	* so we shouldn't return it */
	if (bound <= curbuf->map.size) {
	*pts = curbuf->pts;
	*dts = curbuf->dts;
	return;
	}

	/* Have we found a buffer with pts/dts set? */
	if (curbuf->pts != -1 \|\| curbuf->dts != -1) {
	*pts = curbuf->pts;
	*dts = curbuf->dts;
	return;
	}

	bound -= curbuf->map.size;
	}
	}

	static void
	psmux_stream_write_pes_header (PsMuxStream * stream, guint8 * data)
	{
	guint16 length_to_write;
	guint8 hdr_len = psmux_stream_pes_header_length (stream);

	/* start_code prefix + stream_id + pes_packet_length = 6 bytes */
	data[0] = 0x00;
	data[1] = 0x00;
	data[2] = 0x01;
	data[3] = stream->stream_id;
	data += 4;

	length_to_write = hdr_len - 6 + stream->cur_pes_payload_size;

	psmux_put16 (&data, length_to_write);

	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_FULL_HEADER) {
	guint8 flags = 0;

	/* Not scrambled, original, not-copyrighted, data_alignment specified by flag */
	flags = 0x81;
	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_DATA_ALIGN)
	flags \|= 0x04; /* Enable data_alignment_indicator */
	*data++ = flags;

	/* Flags */
	flags = 0;
	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS)
	flags \|= 0xC0;
	else if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS)
	flags \|= 0x80;
	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_EXT_STREAMID)
	flags \|= 0x01; /* Enable PES_extension_flag */
	*data++ = flags;

	/* Header length is the total pes length,
	* minus the 9 bytes of start codes, flags + hdr_len */
	g_return_if_fail (hdr_len >= 9);
	*data++ = (hdr_len - 9);

	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS_DTS) {
	psmux_put_ts (&data, 0x3, stream->pts);
	psmux_put_ts (&data, 0x1, stream->dts);
	} else if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_WRITE_PTS) {
	psmux_put_ts (&data, 0x2, stream->pts);
	}

	if (stream->pi.flags & PSMUX_PACKET_FLAG_PES_EXT_STREAMID) {
	guint8 ext_len;

	flags = 0x0f; /* preceeding flags all 0 \| (reserved bits) \| PES_extension_flag_2 */
	*data++ = flags;

	ext_len = 1; /* Only writing 1 byte into the extended fields */
	data++ = 0x80 \| ext_len; / marker \| PES_extension_field_length */
	data++ = 0x80 \| stream->stream_id_ext; / stream_id_extension_flag \| extended_stream_id */
	}
	}
	}

	/**
	* psmux_stream_add_data:
	* @stream: a #PsMuxStream
	* @buffer: (transfer full): buffer with data to add
	* @pts: PTS of access unit in @data
	* @dts: DTS of access unit in @data
	*
	* Submit @len bytes of @data into @stream. @pts and @dts can be set to the
	* timestamp (against a 90Hz clock) of the first access unit in @data. A
	* timestamp of -1 for @pts or @dts means unknown.
	*
	* This function takes ownership of @buffer.
	*/
	void
	psmux_stream_add_data (PsMuxStream * stream, GstBuffer * buffer,
	gint64 pts, gint64 dts, gboolean keyunit)
	{
	PsMuxStreamBuffer *packet;

	g_return_if_fail (stream != NULL);

	packet = g_slice_new (PsMuxStreamBuffer);
	packet->buf = buffer;

	if (!gst_buffer_map (packet->buf, &packet->map, GST_MAP_READ)) {
	GST_ERROR ("Failed to map buffer for reading");
	gst_buffer_unref (packet->buf);
	g_slice_free (PsMuxStreamBuffer, packet);
	return;
	}

	packet->keyunit = keyunit;
	packet->pts = pts;
	packet->dts = dts;

	if (stream->bytes_avail == 0)
	stream->last_pts = pts;

	stream->bytes_avail += packet->map.size;
	/* FIXME: perhaps use GstQueueArray instead? */
	stream->buffers = g_list_append (stream->buffers, packet);

	}

	/**
	* psmux_stream_get_es_descrs:
	* @stream: a #PsMuxStream
	* @buf: a buffer to hold the ES descriptor
	* @len: the length used in @buf
	*
	* Write an Elementary Stream Descriptor for @stream into @buf. the number of
	* bytes consumed in @buf will be updated in @len.
	*
	* @buf and @len must be at least #PSMUX_MIN_ES_DESC_LEN.
	*/
	void
	psmux_stream_get_es_descrs (PsMuxStream * stream, guint8 * buf, guint16 * len)
	{
	guint8 *pos;

	g_return_if_fail (stream != NULL);

	if (buf == NULL) {
	if (len != NULL)
	*len = 0;
	return;
	}

	/* Based on the stream type, write out any descriptors to go in the
	* PMT ES_info field */
	pos = buf;

	/* tag (registration_descriptor), length, format_identifier */
	switch (stream->stream_type) {
	case PSMUX_ST_AUDIO_AAC:
	/* FIXME */
	break;
	case PSMUX_ST_VIDEO_MPEG4:
	/* FIXME */
	break;
	case PSMUX_ST_VIDEO_H264:
	*pos++ = 0x05;
	*pos++ = 8;
	pos++ = 0x48; / 'H' */
	pos++ = 0x44; / 'D' */
	pos++ = 0x4D; / 'M' */
	pos++ = 0x56; / 'V' */
	/* FIXME : Not sure about this additional_identification_info */
	*pos++ = 0xFF;
	*pos++ = 0x1B;
	*pos++ = 0x44;
	*pos++ = 0x3F;
	break;
	case PSMUX_ST_VIDEO_DIRAC:
	*pos++ = 0x05;
	*pos++ = 4;
	pos++ = 0x64; / 'd' */
	pos++ = 0x72; / 'r' */
	pos++ = 0x61; / 'a' */
	pos++ = 0x63; / 'c' */
	break;
	case PSMUX_ST_PS_AUDIO_AC3:
	{
	*pos++ = 0x05;
	*pos++ = 4;
	pos++ = 0x41; / 'A' */
	pos++ = 0x43; / 'C' */
	pos++ = 0x2D; / '-' */
	pos++ = 0x33; / '3' */

	/* audio_stream_descriptor () \| ATSC A/52-2001 Annex A
	*
	* descriptor_tag 8 uimsbf
	* descriptor_length 8 uimsbf
	* sample_rate_code 3 bslbf
	* bsid 5 bslbf
	* bit_rate_code 6 bslbf
	* surround_mode 2 bslbf
	* bsmod 3 bslbf
	* num_channels 4 bslbf
	* full_svc 1 bslbf
	* langcod 8 bslbf
	* [...]
	*/
	*pos++ = 0x81;
	*pos++ = 0x04;

	/* 3 bits sample_rate_code, 5 bits hardcoded bsid (default ver 8) */
	switch (stream->audio_sampling) {
	case 48000:
	*pos++ = 0x08;
	break;
	case 44100:
	*pos++ = 0x28;
	break;
	case 32000:
	*pos++ = 0x48;
	break;
	default:
	*pos++ = 0xE8;
	break; /* 48, 44.1 or 32 Khz */
	}

	/* 1 bit bit_rate_limit, 5 bits bit_rate_code, 2 bits suround_mode */
	switch (stream->audio_bitrate) {
	case 32:
	*pos++ = 0x00 << 2;
	break;
	case 40:
	*pos++ = 0x01 << 2;
	break;
	case 48:
	*pos++ = 0x02 << 2;
	break;
	case 56:
	*pos++ = 0x03 << 2;
	break;
	case 64:
	*pos++ = 0x04 << 2;
	break;
	case 80:
	*pos++ = 0x05 << 2;
	break;
	case 96:
	*pos++ = 0x06 << 2;
	break;
	case 112:
	*pos++ = 0x07 << 2;
	break;
	case 128:
	*pos++ = 0x08 << 2;
	break;
	case 160:
	*pos++ = 0x09 << 2;
	break;
	case 192:
	*pos++ = 0x0A << 2;
	break;
	case 224:
	*pos++ = 0x0B << 2;
	break;
	case 256:
	*pos++ = 0x0C << 2;
	break;
	case 320:
	*pos++ = 0x0D << 2;
	break;
	case 384:
	*pos++ = 0x0E << 2;
	break;
	case 448:
	*pos++ = 0x0F << 2;
	break;
	case 512:
	*pos++ = 0x10 << 2;
	break;
	case 576:
	*pos++ = 0x11 << 2;
	break;
	case 640:
	*pos++ = 0x12 << 2;
	break;
	default:
	*pos++ = 0x32 << 2;
	break; /* 640 Kb/s upper limit */
	}

	/* 3 bits bsmod, 4 bits num_channels, 1 bit full_svc */
	switch (stream->audio_channels) {
	case 1:
	*pos++ = 0x01 << 1;
	break; /* 1/0 */
	case 2:
	*pos++ = 0x02 << 1;
	break; /* 2/0 */
	case 3:
	*pos++ = 0x0A << 1;
	break; /* <= 3 */
	case 4:
	*pos++ = 0x0B << 1;
	break; /* <= 4 */
	case 5:
	*pos++ = 0x0C << 1;
	break; /* <= 5 */
	case 6:
	default:
	*pos++ = 0x0D << 1;
	break; /* <= 6 */
	}

	*pos++ = 0x00;

	break;
	}
	case PSMUX_ST_PS_AUDIO_DTS:
	/* FIXME */
	break;
	case PSMUX_ST_PS_AUDIO_LPCM:
	/* FIXME */
	break;
	default:
	break;
	}

	if (len)
	*len = (pos - buf);
	}

	/**
	* psmux_stream_get_pts:
	* @stream: a #PsMuxStream
	*
	* Return the PTS of the last buffer that has had bytes written and
	* which _had_ a PTS in @stream.
	*
	* Returns: the PTS of the last buffer in @stream.
	*/
	guint64
	psmux_stream_get_pts (PsMuxStream * stream)
	{
	g_return_val_if_fail (stream != NULL, -1);

	return stream->last_pts;
	}