root/src/ietf/rtp_pck_3gpp.c

DEFINITIONS

1. rtp_amr_flush
2. gp_rtp_builder_do_amr
3. qes_get_rate_size
4. gp_rtp_builder_do_qcelp
5. rtp_evrc_smv_flush
6. gp_rtp_builder_do_smv
7. gp_rtp_builder_do_h263
8. gp_rtp_builder_do_tx3g
9. gp_rtp_builder_do_dims
10. gf_rtp_ac3_flush
11. gp_rtp_builder_do_ac3

/*
 *                      GPAC - Multimedia Framework C SDK
 *
 *                      Authors: Jean Le Feuvre
 *                      Copyright (c) Telecom ParisTech 2000-2012
 *                                      All rights reserved
 *
 *  This file is part of GPAC / IETF RTP/RTSP/SDP sub-project
 *
 *  GPAC is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  GPAC 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <gpac/internal/ietf_dev.h>

#ifndef GPAC_DISABLE_STREAMING

#include <gpac/constants.h>

static void rtp_amr_flush(GP_RTPPacketizer *builder)
{
        char *hdr;
        u32 hdr_size;
        if (!builder->bytesInPacket) return;
        gf_bs_get_content(builder->pck_hdr, &hdr, &hdr_size);
        gf_bs_del(builder->pck_hdr);
        builder->pck_hdr = NULL;
        /*overwrite last frame F bit*/
        hdr[builder->last_au_sn] &= 0x7F;
        builder->OnData(builder->cbk_obj, hdr, hdr_size, GF_TRUE);
        gf_free(hdr);
        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
        builder->bytesInPacket = 0;
        builder->last_au_sn = 0;
}

GF_Err gp_rtp_builder_do_amr(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize)
{
        u32 offset, rtp_ts, block_size;

        if (!data) {
                rtp_amr_flush(builder);
                return GF_OK;
        }

        rtp_ts = (u32) builder->sl_header.compositionTimeStamp;

        offset = 0;
        while (data_size>offset) {
                u8 ft = (data[offset] & 0x78) >> 3;
                u8 size;

                if (builder->rtp_payt == GF_RTP_PAYT_AMR_WB) {
                        size = (u32)GF_AMR_WB_FRAME_SIZE[ft];
                        block_size = 320;
                } else {
                        size = (u32)GF_AMR_FRAME_SIZE[ft];
                        block_size = 160;
                }

                /*packet full or too long*/
                if (builder->bytesInPacket + 1 + size > builder->Path_MTU)
                        rtp_amr_flush(builder);

                /*need new*/
                if (!builder->bytesInPacket) {
                        builder->rtp_header.TimeStamp = rtp_ts;
                        builder->rtp_header.Marker = 0; /*never set*/
                        builder->rtp_header.SequenceNumber += 1;
                        builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                        assert(builder->pck_hdr==NULL);

                        /*always have header and TOC*/
                        builder->pck_hdr = gf_bs_new(NULL, 0, GF_BITSTREAM_WRITE);
                        /*CMR + res (all 0, no interleaving)*/
                        gf_bs_write_int(builder->pck_hdr, ft, 4);
                        gf_bs_write_int(builder->pck_hdr, 0, 4);
                        builder->bytesInPacket = 1;
                        /*no interleaving*/
                }

                /*F always to 1*/
                gf_bs_write_int(builder->pck_hdr, 1, 1);
                gf_bs_write_int(builder->pck_hdr, ft, 4);
                /*Q*/
                gf_bs_write_int(builder->pck_hdr, (data[offset] & 0x4) ? 1 : 0, 1);
                gf_bs_write_int(builder->pck_hdr, 0, 2);
                builder->bytesInPacket ++;

                /*remove frame type byte*/
                offset++;

                /*add frame data without rate_type byte header*/
                if (builder->OnDataReference) {
                        builder->OnDataReference(builder->cbk_obj, size, offset);
                } else {
                        builder->OnData(builder->cbk_obj, data+offset, size, GF_FALSE);
                }
                builder->last_au_sn++;
                builder->bytesInPacket += size;
                offset += size;
                rtp_ts += block_size;
                assert(builder->bytesInPacket<=builder->Path_MTU);
                /*take care of aggregation, flush if needed*/
                if (builder->last_au_sn==builder->auh_size) rtp_amr_flush(builder);
        }
        return GF_OK;
}

static GFINLINE u8 qes_get_rate_size(u32 idx, const unsigned int *rates, const unsigned int nb_rates)
{
        u32 i;
        for (i=0; i<nb_rates; i++) {
                if (rates[2*i]==idx) return rates[2*i+1];
        }
        return 0;
}

GF_Err gp_rtp_builder_do_qcelp(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize)
{
        u32 offset, rtp_ts;
        u8 hdr;

        if (!data) {
                if (builder->bytesInPacket) builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                builder->bytesInPacket = 0;
                builder->last_au_sn = 0;
                return GF_OK;
        }

        rtp_ts = (u32) builder->sl_header.compositionTimeStamp;


        offset = 0;
        while (data_size>offset) {
                u8 frame_type = data[offset];
                u8 size = qes_get_rate_size(frame_type, GF_QCELP_RATE_TO_SIZE, GF_QCELP_RATE_TO_SIZE_NB);
                /*reserved, not sent)*/
                if (frame_type>=5) {
                        offset += size;
                        continue;
                }
                /*packet full or too long*/
                if (builder->bytesInPacket + size > builder->Path_MTU) {
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                        builder->last_au_sn = 0;
                }

                /*need new*/
                if (!builder->bytesInPacket) {
                        builder->rtp_header.TimeStamp = rtp_ts;
                        builder->rtp_header.Marker = 0; /*never set*/
                        builder->rtp_header.SequenceNumber += 1;
                        builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                        hdr = 0;/*no interleaving*/
                        builder->OnData(builder->cbk_obj, (char*)&hdr, 1, GF_FALSE);
                        builder->bytesInPacket = 1;
                }
                if (builder->OnDataReference) {
                        builder->OnDataReference(builder->cbk_obj, size, offset);
                } else {
                        builder->OnData(builder->cbk_obj, data+offset, size, GF_FALSE);
                }
                builder->bytesInPacket += size;
                offset += size;
                rtp_ts += 160;
                assert(builder->bytesInPacket<=builder->Path_MTU);

                /*take care of aggregation, flush if needed*/
                builder->last_au_sn++;
                if (builder->last_au_sn==builder->auh_size) {
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                        builder->last_au_sn = 0;
                }
        }
        return GF_OK;
}


static void rtp_evrc_smv_flush(GP_RTPPacketizer *builder)
{
        if (!builder->bytesInPacket) return;
        if (builder->auh_size>1) {
                char *hdr;
                u32 hdr_size;
                /*padding*/
                if (builder->last_au_sn % 2) gf_bs_write_int(builder->pck_hdr, 0, 4);
                gf_bs_get_content(builder->pck_hdr, &hdr, &hdr_size);
                gf_bs_del(builder->pck_hdr);
                builder->pck_hdr = NULL;
                /*overwrite count*/
                hdr[0] = 0;
                hdr[1] = builder->last_au_sn-1;/*MMM + frameCount-1*/
                builder->OnData(builder->cbk_obj, hdr, hdr_size, GF_TRUE);
                gf_free(hdr);
        }
        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
        builder->bytesInPacket = 0;
        builder->last_au_sn = 0;
}

GF_Err gp_rtp_builder_do_smv(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize)
{
        u32 offset, rtp_ts;

        if (!data) {
                rtp_evrc_smv_flush(builder);
                return GF_OK;
        }

        rtp_ts = (u32) builder->sl_header.compositionTimeStamp;

        offset = 0;
        while (data_size>offset) {
                u8 frame_type = data[offset];
                u8 size = qes_get_rate_size(frame_type, GF_SMV_EVRC_RATE_TO_SIZE, GF_SMV_EVRC_RATE_TO_SIZE_NB);

                /*reserved, not sent)*/
                if (frame_type>=5) {
                        offset += size;
                        continue;
                }
                /*packet full or too long*/
                if (builder->bytesInPacket + size > builder->Path_MTU)
                        rtp_evrc_smv_flush(builder);

                /*need new*/
                if (!builder->bytesInPacket) {
                        builder->rtp_header.TimeStamp = rtp_ts;
                        builder->rtp_header.Marker = 0; /*never set*/
                        builder->rtp_header.SequenceNumber += 1;
                        builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                        assert(builder->pck_hdr==NULL);

                        if (builder->auh_size>1) {
                                builder->pck_hdr = gf_bs_new(NULL, 0, GF_BITSTREAM_WRITE);
                                /*RRLLLNNN (all 0, no interleaving)*/
                                gf_bs_write_u8(builder->pck_hdr, 0);
                                /*MMM + count-1 : overriden when flushing*/
                                gf_bs_write_u8(builder->pck_hdr, 0);
                                builder->bytesInPacket = 2;
                        }
                }

                /*bundle mode: cat rate byte to TOC, on 4 bits*/
                if (builder->auh_size>1) {
                        gf_bs_write_int(builder->pck_hdr, data[offset], 4);
                        if (!(builder->last_au_sn % 2)) builder->bytesInPacket += 1;
                }
                /*note that EVEN in header-free format the rate_type byte is removed*/
                offset++;
                size--;

                /*add frame data without rate_type byte header*/
                if (builder->OnDataReference) {
                        builder->OnDataReference(builder->cbk_obj, size, offset);
                } else {
                        builder->OnData(builder->cbk_obj, data+offset, size, GF_FALSE);
                }
                builder->last_au_sn++;
                builder->bytesInPacket += size;
                offset += size;
                rtp_ts += 160;
                assert(builder->bytesInPacket<=builder->Path_MTU);
                /*take care of aggregation, flush if needed*/
                if (builder->last_au_sn==builder->auh_size) rtp_evrc_smv_flush(builder);
        }
        return GF_OK;
}

GF_Err gp_rtp_builder_do_h263(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize)
{
        GF_BitStream *bs;
        char hdr[2];
        Bool Pbit;
        u32 offset, size, max_size;

        builder->rtp_header.TimeStamp = (u32) builder->sl_header.compositionTimeStamp;

        /*the H263 hinter doesn't perform inter-sample concatenation*/
        if (!data) return GF_OK;

        Pbit = GF_TRUE;

        /*skip 16 0'ed bits of start code*/
        offset = 2;
        data_size -= 2;
        max_size = builder->Path_MTU - 2;

        while(data_size > 0) {
                if(data_size > max_size) {
                        size = max_size;
                        builder->rtp_header.Marker = 0;
                } else {
                        size = data_size;
                        builder->rtp_header.Marker = 1;
                }

                data_size -= size;

                /*create new RTP Packet */
                builder->rtp_header.SequenceNumber += 1;
                builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);

                bs = gf_bs_new(hdr, 2, GF_BITSTREAM_WRITE);
                gf_bs_write_int(bs, 0, 5);
                gf_bs_write_int(bs, Pbit, 1);
                gf_bs_write_int(bs, 0, 10);
                gf_bs_del(bs);

                /*add header*/
                builder->OnData(builder->cbk_obj, (char*) hdr, 2, GF_TRUE);
                /*add payload*/
                if (builder->OnDataReference)
                        builder->OnDataReference(builder->cbk_obj, size, offset);
                else
                        builder->OnData(builder->cbk_obj, data + offset, size, GF_FALSE);

                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);

                offset += size;
                Pbit = GF_FALSE;
        }
        return GF_OK;
}

GF_Err gp_rtp_builder_do_tx3g(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize, u32 duration, u8 descIndex)
{
        GF_BitStream *bs;
        char *hdr;
        u32 samp_size, txt_size, pay_start, hdr_size, txt_done, cur_frag, nb_frag;
        Bool is_utf_16 = GF_FALSE;

        if (!data) {
                /*flush packet*/
                if (builder->bytesInPacket) {
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                }
                return GF_OK;
        }
        /*cfg packet*/
        txt_size = data[0];
        txt_size <<= 8;
        txt_size |= (unsigned char) data[1];
        /*remove BOM*/
        pay_start = 2;
        if (txt_size>2) {
                /*seems 3GP only accepts BE UTF-16 (no LE, no UTF32)*/
                if (((u8) data[2]==(u8) 0xFE) && ((u8) data[3]==(u8) 0xFF)) {
                        is_utf_16 = GF_TRUE;
                        pay_start = 4;
                        txt_size -= 2;
                }
        }
        samp_size = data_size - pay_start;

        /*if TTU does not fit in packet flush packet*/
        if (builder->bytesInPacket && (builder->bytesInPacket + 3 + 6 + samp_size > builder->Path_MTU)) {
                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                builder->bytesInPacket = 0;
        }

        /*first TTU in packet*/
        if (!builder->bytesInPacket) {
                builder->rtp_header.TimeStamp = (u32) builder->sl_header.compositionTimeStamp;
                builder->rtp_header.Marker = 1;
                builder->rtp_header.SequenceNumber += 1;
                builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
        }
        /*fits entirely*/
        if (builder->bytesInPacket + 3 + 6 + samp_size <= builder->Path_MTU) {
                bs = gf_bs_new(NULL, 0, GF_BITSTREAM_WRITE);
                gf_bs_write_int(bs, is_utf_16, 1);
                gf_bs_write_int(bs, 0, 4);
                gf_bs_write_int(bs, 1, 3);
                gf_bs_write_u16(bs, 8 + samp_size);
                gf_bs_write_u8(bs, descIndex);
                gf_bs_write_u24(bs, duration);
                gf_bs_write_u16(bs, txt_size);
                gf_bs_get_content(bs, &hdr, &hdr_size);
                gf_bs_del(bs);
                builder->OnData(builder->cbk_obj, (char *) hdr, hdr_size, GF_FALSE);
                builder->bytesInPacket += hdr_size;
                gf_free(hdr);

                if (txt_size) {
                        if (builder->OnDataReference) {
                                builder->OnDataReference(builder->cbk_obj, samp_size, pay_start);
                        } else {
                                builder->OnData(builder->cbk_obj, data + pay_start, samp_size, GF_FALSE);
                        }
                        builder->bytesInPacket += samp_size;
                }
                /*disable aggregation*/
                if (!(builder->flags & GP_RTP_PCK_USE_MULTI)) {
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                }
                return GF_OK;
        }
        /*doesn't fit and already data, flush packet*/
        if (builder->bytesInPacket) {
                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                builder->rtp_header.TimeStamp = (u32) builder->sl_header.compositionTimeStamp;
                /*split unit*/
                builder->rtp_header.Marker = 0;
                builder->rtp_header.SequenceNumber += 1;
                builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                builder->bytesInPacket = 0;
        }
        /*write all type2 units (text only) - FIXME: split at char boundaries, NOT SUPPORTED YET*/
        txt_done = 0;
        nb_frag = 1;
        /*all fragments needed for Type2 units*/
        while (txt_done + (builder->Path_MTU-10) < txt_size) {
                txt_done += (builder->Path_MTU-10);
                nb_frag += 1;
        }
        /*all fragments needed for Type3/4 units*/
        txt_done = txt_size;
        while (txt_done + (builder->Path_MTU-7) < samp_size) {
                txt_done += (builder->Path_MTU-7);
                nb_frag += 1;
        }


        cur_frag = 0;
        txt_done = 0;
        while (txt_done<txt_size) {
                u32 size;
                if (txt_done + (builder->Path_MTU-10) < txt_size) {
                        size = builder->Path_MTU-10;
                } else {
                        size = txt_size - txt_done;
                }

                bs = gf_bs_new(NULL, 0, GF_BITSTREAM_WRITE);
                gf_bs_write_int(bs, is_utf_16, 1);
                gf_bs_write_int(bs, 0, 4);
                gf_bs_write_int(bs, 2, 3);
                gf_bs_write_u16(bs, 9 + size);
                gf_bs_write_int(bs, nb_frag, 4);
                gf_bs_write_int(bs, cur_frag, 4);
                gf_bs_write_u24(bs, duration);
                gf_bs_write_u8(bs, descIndex);
                /*SLEN is the full original length minus text len and BOM (put here for buffer allocation purposes)*/
                gf_bs_write_u16(bs, samp_size);
                gf_bs_get_content(bs, &hdr, &hdr_size);
                gf_bs_del(bs);
                builder->OnData(builder->cbk_obj, (char *) hdr, hdr_size, GF_FALSE);
                builder->bytesInPacket += hdr_size;
                gf_free(hdr);

                if (builder->OnDataReference) {
                        builder->OnDataReference(builder->cbk_obj, size, pay_start + txt_done);
                } else {
                        builder->OnData(builder->cbk_obj, data + pay_start + txt_done, size, GF_FALSE);
                }
                builder->bytesInPacket += size;
                cur_frag++;

                /*flush packet*/
                if (cur_frag == nb_frag) {
                        txt_done = txt_size;
                        if (pay_start + txt_done == data_size) {
                                builder->rtp_header.Marker = 1;
                                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                                builder->bytesInPacket = 0;
                        }
                } else {
                        txt_done += size;
                        builder->rtp_header.Marker = 0;
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->rtp_header.SequenceNumber += 1;
                        builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                }
        }

        txt_done = txt_size;

        /*write all modifiers - OPT: split at modifiers boundaries*/
        while (txt_done<samp_size) {
                u32 size, type;
                type = (txt_done == txt_size) ? 3 : 4;

                if (txt_done + (builder->Path_MTU-7) < samp_size) {
                        size = builder->Path_MTU-10;
                } else {
                        size = samp_size - txt_done;
                }

                bs = gf_bs_new(NULL, 0, GF_BITSTREAM_WRITE);
                gf_bs_write_int(bs, is_utf_16, 1);
                gf_bs_write_int(bs, 0, 4);
                gf_bs_write_int(bs, type, 3);
                gf_bs_write_u16(bs, 6 + size);
                gf_bs_write_int(bs, nb_frag, 4);
                gf_bs_write_int(bs, cur_frag, 4);
                gf_bs_write_u24(bs, duration);

                gf_bs_get_content(bs, &hdr, &hdr_size);
                gf_bs_del(bs);
                builder->OnData(builder->cbk_obj, (char *) hdr, hdr_size, GF_FALSE);
                builder->bytesInPacket += hdr_size;
                gf_free(hdr);

                if (builder->OnDataReference) {
                        builder->OnDataReference(builder->cbk_obj, size, pay_start + txt_done);
                } else {
                        builder->OnData(builder->cbk_obj, data + pay_start + txt_done, size, GF_FALSE);
                }
                builder->bytesInPacket += size;
                cur_frag++;
                if (cur_frag==nb_frag) {
                        builder->rtp_header.Marker = 1;
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                } else {
                        builder->rtp_header.Marker = 0;
                        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                        builder->rtp_header.SequenceNumber += 1;
                        builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                        builder->bytesInPacket = 0;
                }
                txt_done += size;
        }
        return GF_OK;
}


GF_Err gp_rtp_builder_do_dims(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize, u32 duration)
{
        u32 frag_state;
        GF_BitStream *bs;
        u32 offset;
        Bool is_last_du;

        /*the DIMS hinter doesn't perform inter-sample concatenation*/
        if (!data) return GF_OK;

        offset = 0;
        builder->rtp_header.TimeStamp = (u32) builder->sl_header.compositionTimeStamp;
        bs = gf_bs_new(data, data_size, GF_BITSTREAM_READ);
        while (offset < data_size) {
                u32 du_offset = 0;
                u32 hdr_offset = 0;
                u32 orig_size, du_size;

                orig_size = du_size = 2+gf_bs_read_u16(bs);
                /*if dims size is >0xFFFF, use our internal hack for large units*/
                if (du_size==2) {
                        orig_size = du_size = 2+gf_bs_read_u32(bs);
                        hdr_offset = 4;
                }
                gf_bs_skip_bytes(bs, du_size-2);

                /*prepare M-bit*/
                is_last_du = (offset+du_size==data_size) ? GF_TRUE : GF_FALSE;

                frag_state = 0;
                while (du_size) {
                        u32 size_offset = 0;
                        u32 size;
                        //size = du_size;

                        /*does not fit, flush required*/
                        if (builder->bytesInPacket && (du_size + 1 + builder->bytesInPacket > builder->Path_MTU)) {
                                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                                builder->bytesInPacket = 0;
                        }

                        /*fragmentation required*/
                        if (du_size + 1 > builder->Path_MTU) {
                                size = builder->Path_MTU - 1;
                                /*first fragment*/
                                if (!frag_state) {
                                        /*size field is skipped !!*/
                                        size_offset = 2 + hdr_offset;
                                        frag_state = 1;

                                        while (du_size - size_offset <= size) {
                                                size--;
                                        }
                                }
                                /*any middle fragment*/
                                else frag_state = 2;

                                builder->rtp_header.Marker = 0;
                        }
                        /*last fragment*/
                        else if (frag_state) {
                                size = du_size;
                                frag_state = 3;
                                builder->rtp_header.Marker = is_last_du;
                        } else {
                                size = du_size;
                                builder->rtp_header.Marker = is_last_du;
                        }

                        if (frag_state && builder->bytesInPacket) {
                                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                                builder->bytesInPacket = 0;
                        }

                        /*need a new packet*/
                        if (!builder->bytesInPacket) {
                                char dims_rtp_hdr[1];

                                /*the unit is critical, increase counter (coded on 3 bits)*/
                                if (! (data[2+hdr_offset] & GF_DIMS_UNIT_P) && (frag_state <= 1) ) {
                                        builder->last_au_sn++;
                                        builder->last_au_sn %= 8;
                                }
                                /*set CTR value*/
                                dims_rtp_hdr[0] = builder->last_au_sn;
                                /*if M-bit is set in the dims unit header, replicate it*/
                                if (data[2+hdr_offset] & (1<<1) ) dims_rtp_hdr[0] |= (1<<6);
                                /*add unit fragmentation type*/
                                dims_rtp_hdr[0] |= (frag_state<<3);

                                builder->rtp_header.SequenceNumber += 1;
                                builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                                builder->OnData(builder->cbk_obj, (char *) dims_rtp_hdr, 1, GF_TRUE);
                                builder->bytesInPacket = 1;
                        }

                        /*add payload*/
                        if (builder->OnDataReference)
                                builder->OnDataReference(builder->cbk_obj, size, offset+du_offset+size_offset);
                        else
                                builder->OnData(builder->cbk_obj, data+offset+du_offset+size_offset, size, GF_FALSE);

                        /*if fragmentation, force packet flush even on last packet since aggregation unit do not
                        use the same packet format*/
                        if (frag_state) {
                                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                                builder->bytesInPacket = 0;
                        } else {
                                builder->bytesInPacket += size;
                        }
                        du_offset += size+size_offset;
                        assert(du_size>= size+size_offset);
                        du_size -= size+size_offset;
                }
                offset += orig_size;
        }
        if (builder->bytesInPacket) {
                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                builder->bytesInPacket = 0;
        }
        gf_bs_del(bs);
        return GF_OK;
}



static void gf_rtp_ac3_flush(GP_RTPPacketizer *builder)
{
        char hdr[2];
        if (!builder->bytesInPacket) return;

        hdr[0] = builder->ac3_ft;
        hdr[1] = builder->last_au_sn;
        builder->OnData(builder->cbk_obj, hdr, 2, GF_TRUE);

        builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
        builder->bytesInPacket = 0;
        builder->last_au_sn = 0;
        builder->ac3_ft = 0;
}

GF_Err gp_rtp_builder_do_ac3(GP_RTPPacketizer *builder, char *data, u32 data_size, u8 IsAUEnd, u32 FullAUSize)
{
        char hdr[2];
        u32 offset, nb_pck;

        /*flush*/
        if (!data) {
                gf_rtp_ac3_flush(builder);
                return GF_OK;
        }

        if (
            /*AU does not fit*/
            (builder->bytesInPacket + data_size > builder->Path_MTU)
            ||
            /*aggregation is not enabled*/
            !(builder->flags & GP_RTP_PCK_USE_MULTI)
            ||
            /*max ptime is exceeded*/
            (builder->max_ptime && ( (u32) builder->sl_header.compositionTimeStamp >= builder->rtp_header.TimeStamp + builder->max_ptime) )

        ) {
                gf_rtp_ac3_flush(builder);
        }

        /*fits*/
        if (builder->bytesInPacket + data_size < builder->Path_MTU) {
                /*need a new packet*/
                if (!builder->bytesInPacket) {
                        builder->rtp_header.TimeStamp = (u32) builder->sl_header.compositionTimeStamp;
                        builder->ac3_ft = 0;
                        builder->rtp_header.Marker = 1;
                        builder->rtp_header.SequenceNumber += 1;
                        builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);
                        /*2 bytes header*/
                        builder->bytesInPacket = 2;
                }

                /*add payload*/
                if (builder->OnDataReference)
                        builder->OnDataReference(builder->cbk_obj, data_size, 0);
                else
                        builder->OnData(builder->cbk_obj, data, data_size, GF_FALSE);

                builder->bytesInPacket += data_size;
                builder->last_au_sn++;
                return GF_OK;
        }

        /*need fragmentation*/
        assert(!builder->bytesInPacket);
        offset = 0;
        nb_pck = data_size / (builder->Path_MTU-2);
        if (data_size % (builder->Path_MTU-2)) nb_pck++;
        builder->last_au_sn = nb_pck;

        while (offset < data_size) {
                u32 pck_size = MIN(data_size-offset, builder->Path_MTU-2);

                builder->rtp_header.Marker = 0;
                builder->rtp_header.TimeStamp = (u32) builder->sl_header.compositionTimeStamp;
                builder->rtp_header.SequenceNumber += 1;

                if (!offset) {
                        builder->ac3_ft = (pck_size > 5*data_size/8) ? 1 : 2;
                } else {
                        builder->ac3_ft = 3;
                        if (offset + pck_size == data_size)
                                builder->rtp_header.Marker = 1;
                }
                builder->OnNewPacket(builder->cbk_obj, &builder->rtp_header);

                hdr[0] = builder->ac3_ft;
                hdr[1] = builder->last_au_sn;
                builder->OnData(builder->cbk_obj, hdr, 2, GF_TRUE);

                /*add payload*/
                if (builder->OnDataReference)
                        builder->OnDataReference(builder->cbk_obj, pck_size, offset);
                else
                        builder->OnData(builder->cbk_obj, data+offset, pck_size, GF_FALSE);

                builder->OnPacketDone(builder->cbk_obj, &builder->rtp_header);
                offset += pck_size;
                builder->bytesInPacket = 0;
        }

        return GF_OK;
}

#endif /*GPAC_DISABLE_STREAMING*/