PeerStreamer

/*

 * MPEG2 transport stream (aka DVB) mux

 * Copyright (c) 2003 Fabrice Bellard.

 *

 * This library 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 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avformat.h"

#include "mpegts.h"

/* write DVB SI sections */

static const uint32_t crc_table[256] = {

        0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,

        0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,

        0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,

        0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,

        0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,

        0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,

        0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,

        0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,

        0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,

        0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,

        0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,

        0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,

        0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,

        0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,

        0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,

        0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,

        0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,

        0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,

        0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,

        0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,

        0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,

        0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,

        0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,

        0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,

        0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,

        0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,

        0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,

        0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,

        0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,

        0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,

        0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,

        0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,

        0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,

        0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,

        0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,

        0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,

        0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,

        0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,

        0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,

        0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,

        0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,

        0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,

        0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4

};

unsigned int mpegts_crc32(const uint8_t *data, int len)

{

    register int i;

    unsigned int crc = 0xffffffff;

    for (i=0; i<len; i++)

        crc = (crc << 8) ^ crc_table[((crc >> 24) ^ *data++) & 0xff];

    return crc;

}

/*********************************************/

/* mpegts section writer */

typedef struct MpegTSSection {

    int pid;

    int cc;

    void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);

    void *opaque;

} MpegTSSection;

/* NOTE: 4 bytes must be left at the end for the crc32 */

void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)

{

    unsigned int crc;

    unsigned char packet[TS_PACKET_SIZE];

    const unsigned char *buf_ptr;

    unsigned char *q;

    int first, b, len1, left;

    crc = mpegts_crc32(buf, len - 4);

    buf[len - 4] = (crc >> 24) & 0xff;

    buf[len - 3] = (crc >> 16) & 0xff;

    buf[len - 2] = (crc >> 8) & 0xff;

    buf[len - 1] = (crc) & 0xff;

    /* send each packet */

    buf_ptr = buf;

    while (len > 0) {

        first = (buf == buf_ptr);

        q = packet;

        *q++ = 0x47;

        b = (s->pid >> 8);

        if (first)

            b |= 0x40;

        *q++ = b;

        *q++ = s->pid;

        s->cc = (s->cc + 1) & 0xf;

        *q++ = 0x10 | s->cc;

        if (first)

            *q++ = 0; /* 0 offset */

        len1 = TS_PACKET_SIZE - (q - packet);

        if (len1 > len)

            len1 = len;

        memcpy(q, buf_ptr, len1);

        q += len1;

        /* add known padding data */

        left = TS_PACKET_SIZE - (q - packet);

        if (left > 0)

            memset(q, 0xff, left);

        s->write_packet(s, packet);

        buf_ptr += len1;

        len -= len1;

    }

}

static inline void put16(uint8_t **q_ptr, int val)

{

    uint8_t *q;

    q = *q_ptr;

    *q++ = val >> 8;

    *q++ = val;

    *q_ptr = q;

}

int mpegts_write_section1(MpegTSSection *s, int tid, int id,

                          int version, int sec_num, int last_sec_num,

                          uint8_t *buf, int len)

{

    uint8_t section[1024], *q;

    unsigned int tot_len;

    tot_len = 3 + 5 + len + 4;

    /* check if not too big */

    if (tot_len > 1024)

        return -1;

    q = section;

    *q++ = tid;

    put16(&q, 0xb000 | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */

    put16(&q, id);

    *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */

    *q++ = sec_num;

    *q++ = last_sec_num;

    memcpy(q, buf, len);

    mpegts_write_section(s, section, tot_len);

    return 0;

}

/*********************************************/

/* mpegts writer */

#define DEFAULT_PMT_START_PID   0x1000

#define DEFAULT_START_PID       0x0100

#define DEFAULT_PROVIDER_NAME   "FFmpeg"

#define DEFAULT_SERVICE_NAME    "Service01"

/* default network id, transport stream and service identifiers */

#define DEFAULT_ONID            0x0001

#define DEFAULT_TSID            0x0001

#define DEFAULT_SID             0x0001

/* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */

#define DEFAULT_PES_HEADER_FREQ 16

#define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)

/* we retransmit the SI info at this rate */

#define SDT_RETRANS_TIME 500

#define PAT_RETRANS_TIME 100

#define PCR_RETRANS_TIME 20

typedef struct MpegTSWriteStream {

    struct MpegTSService *service;

    int pid; /* stream associated pid */

    int cc;

    int payload_index;

    int64_t payload_pts;

    uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];

} MpegTSWriteStream;

typedef struct MpegTSService {

    MpegTSSection pmt; /* MPEG2 pmt table context */

    int sid;           /* service ID */

    char *name;

    char *provider_name;

    int pcr_pid;

    int pcr_packet_count;

    int pcr_packet_freq;

} MpegTSService;

typedef struct MpegTSWrite {

    MpegTSSection pat; /* MPEG2 pat table */

    MpegTSSection sdt; /* MPEG2 sdt table context */

    MpegTSService **services;

    int sdt_packet_count;

    int sdt_packet_freq;

    int pat_packet_count;

    int pat_packet_freq;

    int nb_services;

    int onid;

    int tsid;

} MpegTSWrite;

static void mpegts_write_pat(AVFormatContext *s)

{

    MpegTSWrite *ts = s->priv_data;

    MpegTSService *service;

    uint8_t data[1012], *q;

    int i;

    q = data;

    for(i = 0; i < ts->nb_services; i++) {

        service = ts->services[i];

        put16(&q, service->sid);

        put16(&q, 0xe000 | service->pmt.pid);

    }

    mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,

                          data, q - data);

}

static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)

{

    //    MpegTSWrite *ts = s->priv_data;

    uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;

    int val, stream_type, i;

    q = data;

    put16(&q, 0xe000 | service->pcr_pid);

    program_info_length_ptr = q;

    q += 2; /* patched after */

    /* put program info here */

    val = 0xf000 | (q - program_info_length_ptr - 2);

    program_info_length_ptr[0] = val >> 8;

    program_info_length_ptr[1] = val;

    for(i = 0; i < s->nb_streams; i++) {

        AVStream *st = s->streams[i];

        MpegTSWriteStream *ts_st = st->priv_data;

        switch(st->codec->codec_id) {

        case CODEC_ID_MPEG1VIDEO:

        case CODEC_ID_MPEG2VIDEO:

            stream_type = STREAM_TYPE_VIDEO_MPEG2;

            break;

        case CODEC_ID_MPEG4:

            stream_type = STREAM_TYPE_VIDEO_MPEG4;

            break;

        case CODEC_ID_H264:

            stream_type = STREAM_TYPE_VIDEO_H264;

            break;

        case CODEC_ID_MP2:

        case CODEC_ID_MP3:

            stream_type = STREAM_TYPE_AUDIO_MPEG1;

            break;

        case CODEC_ID_AAC:

            stream_type = STREAM_TYPE_AUDIO_AAC;

            break;

        case CODEC_ID_AC3:

            stream_type = STREAM_TYPE_AUDIO_AC3;

            break;

        default:

            stream_type = STREAM_TYPE_PRIVATE_DATA;

            break;

        }

        *q++ = stream_type;

        put16(&q, 0xe000 | ts_st->pid);

        desc_length_ptr = q;

        q += 2; /* patched after */

        /* write optional descriptors here */

        switch(st->codec->codec_type) {

        case CODEC_TYPE_AUDIO:

            if (strlen(st->language) == 3) {

                *q++ = 0x0a; /* ISO 639 language descriptor */

                *q++ = 4;

                *q++ = st->language[0];

                *q++ = st->language[1];

                *q++ = st->language[2];

                *q++ = 0; /* undefined type */

            }

            break;

        case CODEC_TYPE_SUBTITLE:

            {

                const char *language;

                language = st->language;

                if (strlen(language) != 3)

                    language = "eng";

                *q++ = 0x59;

                *q++ = 8;

                *q++ = language[0];

                *q++ = language[1];

                *q++ = language[2];

                *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */

                put16(&q, 1); /* page id */

                put16(&q, 1); /* ancillary page id */

            }

            break;

        }

        val = 0xf000 | (q - desc_length_ptr - 2);

        desc_length_ptr[0] = val >> 8;

        desc_length_ptr[1] = val;

    }

    mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,

                          data, q - data);

}

/* NOTE: str == NULL is accepted for an empty string */

static void putstr8(uint8_t **q_ptr, const char *str)

{

    uint8_t *q;

    int len;

    q = *q_ptr;

    if (!str)

        len = 0;

    else

        len = strlen(str);

    *q++ = len;

    memcpy(q, str, len);

    q += len;

    *q_ptr = q;

}

static void mpegts_write_sdt(AVFormatContext *s)

{

    MpegTSWrite *ts = s->priv_data;

    MpegTSService *service;

    uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;

    int i, running_status, free_ca_mode, val;

    q = data;

    put16(&q, ts->onid);

    *q++ = 0xff;

    for(i = 0; i < ts->nb_services; i++) {

        service = ts->services[i];

        put16(&q, service->sid);

        *q++ = 0xfc | 0x00; /* currently no EIT info */

        desc_list_len_ptr = q;

        q += 2;

        running_status = 4; /* running */

        free_ca_mode = 0;

        /* write only one descriptor for the service name and provider */

        *q++ = 0x48;

        desc_len_ptr = q;

        q++;

        *q++ = 0x01; /* digital television service */

        putstr8(&q, service->provider_name);

        putstr8(&q, service->name);

        desc_len_ptr[0] = q - desc_len_ptr - 1;

        /* fill descriptor length */

        val = (running_status << 13) | (free_ca_mode << 12) |

            (q - desc_list_len_ptr - 2);

        desc_list_len_ptr[0] = val >> 8;

        desc_list_len_ptr[1] = val;

    }

    mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,

                          data, q - data);

}

static MpegTSService *mpegts_add_service(MpegTSWrite *ts,

                                         int sid,

                                         const char *provider_name,

                                         const char *name)

{

    MpegTSService *service;

    service = av_mallocz(sizeof(MpegTSService));

    if (!service)

        return NULL;

    service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;

    service->sid = sid;

    service->provider_name = av_strdup(provider_name);

    service->name = av_strdup(name);

    service->pcr_pid = 0x1fff;

    dynarray_add(&ts->services, &ts->nb_services, service);

    return service;

}

static void section_write_packet(MpegTSSection *s, const uint8_t *packet)

{

    AVFormatContext *ctx = s->opaque;

    put_buffer(&ctx->pb, packet, TS_PACKET_SIZE);

}

static int mpegts_write_header(AVFormatContext *s)

{

    MpegTSWrite *ts = s->priv_data;

    MpegTSWriteStream *ts_st;

    MpegTSService *service;

    AVStream *st;

    int i, total_bit_rate;

    const char *service_name;

    ts->tsid = DEFAULT_TSID;

    ts->onid = DEFAULT_ONID;

    /* allocate a single DVB service */

    service_name = s->title;

    if (service_name[0] == '\0')

        service_name = DEFAULT_SERVICE_NAME;

    service = mpegts_add_service(ts, DEFAULT_SID,

                                 DEFAULT_PROVIDER_NAME, service_name);

    service->pmt.write_packet = section_write_packet;

    service->pmt.opaque = s;

    ts->pat.pid = PAT_PID;

    ts->pat.cc = 0;

    ts->pat.write_packet = section_write_packet;

    ts->pat.opaque = s;

    ts->sdt.pid = SDT_PID;

    ts->sdt.cc = 0;

    ts->sdt.write_packet = section_write_packet;

    ts->sdt.opaque = s;

    /* assign pids to each stream */

    total_bit_rate = 0;

    for(i = 0;i < s->nb_streams; i++) {

        st = s->streams[i];

        ts_st = av_mallocz(sizeof(MpegTSWriteStream));

        if (!ts_st)

            goto fail;

        st->priv_data = ts_st;

        ts_st->service = service;

        ts_st->pid = DEFAULT_START_PID + i;

        ts_st->payload_pts = AV_NOPTS_VALUE;

        /* update PCR pid by using the first video stream */

        if (st->codec->codec_type == CODEC_TYPE_VIDEO &&

            service->pcr_pid == 0x1fff)

            service->pcr_pid = ts_st->pid;

        total_bit_rate += st->codec->bit_rate;

    }

    /* if no video stream, use the first stream as PCR */

    if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {

        ts_st = s->streams[0]->priv_data;

        service->pcr_pid = ts_st->pid;

    }

    if (total_bit_rate <= 8 * 1024)

        total_bit_rate = 8 * 1024;

    service->pcr_packet_freq = (total_bit_rate * PCR_RETRANS_TIME) /

        (TS_PACKET_SIZE * 8 * 1000);

    ts->sdt_packet_freq = (total_bit_rate * SDT_RETRANS_TIME) /

        (TS_PACKET_SIZE * 8 * 1000);

    ts->pat_packet_freq = (total_bit_rate * PAT_RETRANS_TIME) /

        (TS_PACKET_SIZE * 8 * 1000);

#if 0

    printf("%d %d %d\n",

           total_bit_rate, ts->sdt_packet_freq, ts->pat_packet_freq);

#endif

    /* write info at the start of the file, so that it will be fast to

       find them */

    mpegts_write_sdt(s);

    mpegts_write_pat(s);

    for(i = 0; i < ts->nb_services; i++) {

        mpegts_write_pmt(s, ts->services[i]);

    }

    put_flush_packet(&s->pb);

    return 0;

 fail:

    for(i = 0;i < s->nb_streams; i++) {

        st = s->streams[i];

        av_free(st->priv_data);

    }

    return -1;

}

/* send SDT, PAT and PMT tables regulary */

static void retransmit_si_info(AVFormatContext *s)

{

    MpegTSWrite *ts = s->priv_data;

    int i;

    if (++ts->sdt_packet_count == ts->sdt_packet_freq) {

        ts->sdt_packet_count = 0;

        mpegts_write_sdt(s);

    }

    if (++ts->pat_packet_count == ts->pat_packet_freq) {

        ts->pat_packet_count = 0;

        mpegts_write_pat(s);

        for(i = 0; i < ts->nb_services; i++) {

            mpegts_write_pmt(s, ts->services[i]);

        }

    }

}

/* NOTE: pes_data contains all the PES packet */

static void mpegts_write_pes(AVFormatContext *s, AVStream *st,

                             const uint8_t *payload, int payload_size,

                             int64_t pts)

{

    MpegTSWriteStream *ts_st = st->priv_data;

    uint8_t buf[TS_PACKET_SIZE];

    uint8_t *q;

    int val, is_start, len, header_len, write_pcr, private_code;

    int afc_len, stuffing_len;

    int64_t pcr = -1; /* avoid warning */

    is_start = 1;

    while (payload_size > 0) {

        retransmit_si_info(s);

        write_pcr = 0;

        if (ts_st->pid == ts_st->service->pcr_pid) {

            ts_st->service->pcr_packet_count++;

            if (ts_st->service->pcr_packet_count >=

                ts_st->service->pcr_packet_freq) {

                ts_st->service->pcr_packet_count = 0;

                write_pcr = 1;

                /* XXX: this is incorrect, but at least we have a PCR

                   value */

                pcr = pts;

            }

        }

        /* prepare packet header */

        q = buf;

        *q++ = 0x47;

        val = (ts_st->pid >> 8);

        if (is_start)

            val |= 0x40;

        *q++ = val;

        *q++ = ts_st->pid;

        *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);

        ts_st->cc = (ts_st->cc + 1) & 0xf;

        if (write_pcr) {

            *q++ = 7; /* AFC length */

            *q++ = 0x10; /* flags: PCR present */

            *q++ = pcr >> 25;

            *q++ = pcr >> 17;

            *q++ = pcr >> 9;

            *q++ = pcr >> 1;

            *q++ = (pcr & 1) << 7;

            *q++ = 0;

        }

        if (is_start) {

            /* write PES header */

            *q++ = 0x00;

            *q++ = 0x00;

            *q++ = 0x01;

            private_code = 0;

            if (st->codec->codec_type == CODEC_TYPE_VIDEO) {

                *q++ = 0xe0;

            } else if (st->codec->codec_type == CODEC_TYPE_AUDIO &&

                       (st->codec->codec_id == CODEC_ID_MP2 ||

                        st->codec->codec_id == CODEC_ID_MP3)) {

                *q++ = 0xc0;

            } else {

                *q++ = 0xbd;

                if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {

                    private_code = 0x20;

                }

            }

            if (pts != AV_NOPTS_VALUE)

                header_len = 8;

            else

                header_len = 3;

            if (private_code != 0)

                header_len++;

            len = payload_size + header_len;

            *q++ = len >> 8;

            *q++ = len;

            val = 0x80;

            /* data alignment indicator is required for subtitle data */

            if (st->codec->codec_type == CODEC_TYPE_SUBTITLE)

                val |= 0x04;

            *q++ = val;

            if (pts != AV_NOPTS_VALUE) {

                *q++ = 0x80; /* PTS only */

                *q++ = 0x05; /* header len */

                val = (0x02 << 4) |

                    (((pts >> 30) & 0x07) << 1) | 1;

                *q++ = val;

                val = (((pts >> 15) & 0x7fff) << 1) | 1;

                *q++ = val >> 8;

                *q++ = val;

                val = (((pts) & 0x7fff) << 1) | 1;

                *q++ = val >> 8;

                *q++ = val;

            } else {

                *q++ = 0x00;

                *q++ = 0x00;

            }

            if (private_code != 0)

                *q++ = private_code;

            is_start = 0;

        }

        /* header size */

        header_len = q - buf;

        /* data len */

        len = TS_PACKET_SIZE - header_len;

        if (len > payload_size)

            len = payload_size;

        stuffing_len = TS_PACKET_SIZE - header_len - len;

        if (stuffing_len > 0) {

            /* add stuffing with AFC */

            if (buf[3] & 0x20) {

                /* stuffing already present: increase its size */

                afc_len = buf[4] + 1;

                memmove(buf + 4 + afc_len + stuffing_len,

                        buf + 4 + afc_len,

                        header_len - (4 + afc_len));

                buf[4] += stuffing_len;

                memset(buf + 4 + afc_len, 0xff, stuffing_len);

            } else {

                /* add stuffing */

                memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);

                buf[3] |= 0x20;

                buf[4] = stuffing_len - 1;

                if (stuffing_len >= 2) {

                    buf[5] = 0x00;

                    memset(buf + 6, 0xff, stuffing_len - 2);

                }

            }

        }

        memcpy(buf + TS_PACKET_SIZE - len, payload, len);

        payload += len;

        payload_size -= len;

        put_buffer(&s->pb, buf, TS_PACKET_SIZE);

    }

    put_flush_packet(&s->pb);

}

static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    AVStream *st = s->streams[pkt->stream_index];

    int size= pkt->size;

    uint8_t *buf= pkt->data;

    MpegTSWriteStream *ts_st = st->priv_data;

    int len, max_payload_size;

    if (st->codec->codec_type == CODEC_TYPE_SUBTITLE) {

        /* for subtitle, a single PES packet must be generated */

        mpegts_write_pes(s, st, buf, size, pkt->pts);

        return 0;

    }

    max_payload_size = DEFAULT_PES_PAYLOAD_SIZE;

    while (size > 0) {

        len = max_payload_size - ts_st->payload_index;

        if (len > size)

            len = size;

        memcpy(ts_st->payload + ts_st->payload_index, buf, len);

        buf += len;

        size -= len;

        ts_st->payload_index += len;

        if (ts_st->payload_pts == AV_NOPTS_VALUE)

            ts_st->payload_pts = pkt->pts;

        if (ts_st->payload_index >= max_payload_size) {

            mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,

                             ts_st->payload_pts);

            ts_st->payload_pts = AV_NOPTS_VALUE;

            ts_st->payload_index = 0;

        }

    }

    return 0;

}

static int mpegts_write_end(AVFormatContext *s)

{

    MpegTSWrite *ts = s->priv_data;

    MpegTSWriteStream *ts_st;

    MpegTSService *service;

    AVStream *st;

    int i;

    /* flush current packets */

    for(i = 0; i < s->nb_streams; i++) {

        st = s->streams[i];

        ts_st = st->priv_data;

        if (ts_st->payload_index > 0) {

            mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,

                             ts_st->payload_pts);

        }

    }

    put_flush_packet(&s->pb);

    for(i = 0; i < ts->nb_services; i++) {

        service = ts->services[i];

        av_freep(&service->provider_name);

        av_freep(&service->name);

        av_free(service);

    }

    av_free(ts->services);

    return 0;

}

AVOutputFormat mpegts_mux = {

    "mpegts",

    "MPEG2 transport stream format",

    "video/x-mpegts",

    "ts",

    sizeof(MpegTSWrite),

    CODEC_ID_MP2,

    CODEC_ID_MPEG2VIDEO,

    mpegts_write_header,

    mpegts_write_packet,

    mpegts_write_end,

};