PeerStreamer

/*

 * MPEG2 transport stream (aka DVB) demuxer

 * Copyright (c) 2002-2003 Fabrice Bellard

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg 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 FFmpeg; if not, write to the Free Software

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

 */

//#define DEBUG

//#define DEBUG_SEEK

#include "libavutil/crc.h"

#include "libavutil/intreadwrite.h"

#include "libavcodec/bytestream.h"

#include "avformat.h"

#include "mpegts.h"

#include "internal.h"

/* 1.0 second at 24Mbit/s */

#define MAX_SCAN_PACKETS 32000

/* maximum size in which we look for synchronisation if

   synchronisation is lost */

#define MAX_RESYNC_SIZE 4096

#define MAX_PES_PAYLOAD 200*1024

typedef struct PESContext PESContext;

static PESContext* add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid, int stream_type);

enum MpegTSFilterType {

    MPEGTS_PES,

    MPEGTS_SECTION,

};

typedef struct MpegTSFilter MpegTSFilter;

typedef int PESCallback(MpegTSFilter *f, const uint8_t *buf, int len, int is_start, int64_t pos);

typedef struct MpegTSPESFilter {

    PESCallback *pes_cb;

    void *opaque;

} MpegTSPESFilter;

typedef void SectionCallback(MpegTSFilter *f, const uint8_t *buf, int len);

typedef void SetServiceCallback(void *opaque, int ret);

typedef struct MpegTSSectionFilter {

    int section_index;

    int section_h_size;

    uint8_t *section_buf;

    unsigned int check_crc:1;

    unsigned int end_of_section_reached:1;

    SectionCallback *section_cb;

    void *opaque;

} MpegTSSectionFilter;

struct MpegTSFilter {

    int pid;

    int last_cc; /* last cc code (-1 if first packet) */

    enum MpegTSFilterType type;

    union {

        MpegTSPESFilter pes_filter;

        MpegTSSectionFilter section_filter;

    } u;

};

#define MAX_PIDS_PER_PROGRAM 64

struct Program {

    unsigned int id; //program id/service id

    unsigned int nb_pids;

    unsigned int pids[MAX_PIDS_PER_PROGRAM];

};

struct MpegTSContext {

    /* user data */

    AVFormatContext *stream;

    /** raw packet size, including FEC if present            */

    int raw_packet_size;

    int pos47;

    /** if true, all pids are analyzed to find streams       */

    int auto_guess;

    /** compute exact PCR for each transport stream packet   */

    int mpeg2ts_compute_pcr;

    int64_t cur_pcr;    /**< used to estimate the exact PCR  */

    int pcr_incr;       /**< used to estimate the exact PCR  */

    /* data needed to handle file based ts */

    /** stop parsing loop                                    */

    int stop_parse;

    /** packet containing Audio/Video data                   */

    AVPacket *pkt;

    /** to detect seek                                       */

    int64_t last_pos;

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

    /* private mpegts data */

    /* scan context */

    /** structure to keep track of Program->pids mapping     */

    unsigned int nb_prg;

    struct Program *prg;

    /** filters for various streams specified by PMT + for the PAT and PMT */

    MpegTSFilter *pids[NB_PID_MAX];

};

/* TS stream handling */

enum MpegTSState {

    MPEGTS_HEADER = 0,

    MPEGTS_PESHEADER_FILL,

    MPEGTS_PAYLOAD,

    MPEGTS_SKIP,

};

/* enough for PES header + length */

#define PES_START_SIZE 9

#define MAX_PES_HEADER_SIZE (9 + 255)

struct PESContext {

    int pid;

    int pcr_pid; /**< if -1 then all packets containing PCR are considered */

    int stream_type;

    MpegTSContext *ts;

    AVFormatContext *stream;

    AVStream *st;

    enum MpegTSState state;

    /* used to get the format */

    int data_index;

    int total_size;

    int pes_header_size;

    int64_t pts, dts;

    int64_t ts_packet_pos; /**< position of first TS packet of this PES packet */

    uint8_t header[MAX_PES_HEADER_SIZE];

    uint8_t *buffer;

};

extern AVInputFormat mpegts_demuxer;

static void clear_program(MpegTSContext *ts, unsigned int programid)

{

    int i;

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

        if(ts->prg[i].id == programid)

            ts->prg[i].nb_pids = 0;

}

static void clear_programs(MpegTSContext *ts)

{

    av_freep(&ts->prg);

    ts->nb_prg=0;

}

static void add_pat_entry(MpegTSContext *ts, unsigned int programid)

{

    struct Program *p;

    void *tmp = av_realloc(ts->prg, (ts->nb_prg+1)*sizeof(struct Program));

    if(!tmp)

        return;

    ts->prg = tmp;

    p = &ts->prg[ts->nb_prg];

    p->id = programid;

    p->nb_pids = 0;

    ts->nb_prg++;

}

static void add_pid_to_pmt(MpegTSContext *ts, unsigned int programid, unsigned int pid)

{

    int i;

    struct Program *p = NULL;

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

        if(ts->prg[i].id == programid) {

            p = &ts->prg[i];

            break;

        }

    }

    if(!p)

        return;

    if(p->nb_pids >= MAX_PIDS_PER_PROGRAM)

        return;

    p->pids[p->nb_pids++] = pid;

}

/**

 * \brief discard_pid() decides if the pid is to be discarded according

 *                      to caller's programs selection

 * \param ts    : - TS context

 * \param pid   : - pid

 * \return 1 if the pid is only comprised in programs that have .discard=AVDISCARD_ALL

 *         0 otherwise

 */

static int discard_pid(MpegTSContext *ts, unsigned int pid)

{

    int i, j, k;

    int used = 0, discarded = 0;

    struct Program *p;

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

        p = &ts->prg[i];

        for(j=0; j<p->nb_pids; j++) {

            if(p->pids[j] != pid)

                continue;

            //is program with id p->id set to be discarded?

            for(k=0; k<ts->stream->nb_programs; k++) {

                if(ts->stream->programs[k]->id == p->id) {

                    if(ts->stream->programs[k]->discard == AVDISCARD_ALL)

                        discarded++;

                    else

                        used++;

                }

            }

        }

    }

    return !used && discarded;

}

/**

 *  Assembles PES packets out of TS packets, and then calls the "section_cb"

 *  function when they are complete.

 */

static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1,

                               const uint8_t *buf, int buf_size, int is_start)

{

    MpegTSSectionFilter *tss = &tss1->u.section_filter;

    int len;

    if (is_start) {

        memcpy(tss->section_buf, buf, buf_size);

        tss->section_index = buf_size;

        tss->section_h_size = -1;

        tss->end_of_section_reached = 0;

    } else {

        if (tss->end_of_section_reached)

            return;

        len = 4096 - tss->section_index;

        if (buf_size < len)

            len = buf_size;

        memcpy(tss->section_buf + tss->section_index, buf, len);

        tss->section_index += len;

    }

    /* compute section length if possible */

    if (tss->section_h_size == -1 && tss->section_index >= 3) {

        len = (AV_RB16(tss->section_buf + 1) & 0xfff) + 3;

        if (len > 4096)

            return;

        tss->section_h_size = len;

    }

    if (tss->section_h_size != -1 && tss->section_index >= tss->section_h_size) {

        tss->end_of_section_reached = 1;

        if (!tss->check_crc ||

            av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1,

                   tss->section_buf, tss->section_h_size) == 0)

            tss->section_cb(tss1, tss->section_buf, tss->section_h_size);

    }

}

static MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid,

                                         SectionCallback *section_cb, void *opaque,

                                         int check_crc)

{

    MpegTSFilter *filter;

    MpegTSSectionFilter *sec;

    dprintf(ts->stream, "Filter: pid=0x%x\n", pid);

    if (pid >= NB_PID_MAX || ts->pids[pid])

        return NULL;

    filter = av_mallocz(sizeof(MpegTSFilter));

    if (!filter)

        return NULL;

    ts->pids[pid] = filter;

    filter->type = MPEGTS_SECTION;

    filter->pid = pid;

    filter->last_cc = -1;

    sec = &filter->u.section_filter;

    sec->section_cb = section_cb;

    sec->opaque = opaque;

    sec->section_buf = av_malloc(MAX_SECTION_SIZE);

    sec->check_crc = check_crc;

    if (!sec->section_buf) {

        av_free(filter);

        return NULL;

    }

    return filter;

}

static MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid,

                                     PESCallback *pes_cb,

                                     void *opaque)

{

    MpegTSFilter *filter;

    MpegTSPESFilter *pes;

    if (pid >= NB_PID_MAX || ts->pids[pid])

        return NULL;

    filter = av_mallocz(sizeof(MpegTSFilter));

    if (!filter)

        return NULL;

    ts->pids[pid] = filter;

    filter->type = MPEGTS_PES;

    filter->pid = pid;

    filter->last_cc = -1;

    pes = &filter->u.pes_filter;

    pes->pes_cb = pes_cb;

    pes->opaque = opaque;

    return filter;

}

static void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)

{

    int pid;

    pid = filter->pid;

    if (filter->type == MPEGTS_SECTION)

        av_freep(&filter->u.section_filter.section_buf);

    else if (filter->type == MPEGTS_PES) {

        PESContext *pes = filter->u.pes_filter.opaque;

        av_freep(&pes->buffer);

        /* referenced private data will be freed later in

         * av_close_input_stream */

        if (!((PESContext *)filter->u.pes_filter.opaque)->st) {

            av_freep(&filter->u.pes_filter.opaque);

        }

    }

    av_free(filter);

    ts->pids[pid] = NULL;

}

static int analyze(const uint8_t *buf, int size, int packet_size, int *index){

    int stat[packet_size];

    int i;

    int x=0;

    int best_score=0;

    memset(stat, 0, packet_size*sizeof(int));

    for(x=i=0; i<size-3; i++){

        if(buf[i] == 0x47 && !(buf[i+1] & 0x80) && (buf[i+3] & 0x30)){

            stat[x]++;

            if(stat[x] > best_score){

                best_score= stat[x];

                if(index) *index= x;

            }

        }

        x++;

        if(x == packet_size) x= 0;

    }

    return best_score;

}

/* autodetect fec presence. Must have at least 1024 bytes  */

static int get_packet_size(const uint8_t *buf, int size)

{

    int score, fec_score, dvhs_score;

    if (size < (TS_FEC_PACKET_SIZE * 5 + 1))

        return -1;

    score    = analyze(buf, size, TS_PACKET_SIZE, NULL);

    dvhs_score    = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL);

    fec_score= analyze(buf, size, TS_FEC_PACKET_SIZE, NULL);

//    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);

    if     (score > fec_score && score > dvhs_score) return TS_PACKET_SIZE;

    else if(dvhs_score > score && dvhs_score > fec_score) return TS_DVHS_PACKET_SIZE;

    else if(score < fec_score && dvhs_score < fec_score) return TS_FEC_PACKET_SIZE;

    else                       return -1;

}

typedef struct SectionHeader {

    uint8_t tid;

    uint16_t id;

    uint8_t version;

    uint8_t sec_num;

    uint8_t last_sec_num;

} SectionHeader;

static inline int get8(const uint8_t **pp, const uint8_t *p_end)

{

    const uint8_t *p;

    int c;

    p = *pp;

    if (p >= p_end)

        return -1;

    c = *p++;

    *pp = p;

    return c;

}

static inline int get16(const uint8_t **pp, const uint8_t *p_end)

{

    const uint8_t *p;

    int c;

    p = *pp;

    if ((p + 1) >= p_end)

        return -1;

    c = AV_RB16(p);

    p += 2;

    *pp = p;

    return c;

}

/* read and allocate a DVB string preceeded by its length */

static char *getstr8(const uint8_t **pp, const uint8_t *p_end)

{

    int len;

    const uint8_t *p;

    char *str;

    p = *pp;

    len = get8(&p, p_end);

    if (len < 0)

        return NULL;

    if ((p + len) > p_end)

        return NULL;

    str = av_malloc(len + 1);

    if (!str)

        return NULL;

    memcpy(str, p, len);

    str[len] = '\0';

    p += len;

    *pp = p;

    return str;

}

static int parse_section_header(SectionHeader *h,

                                const uint8_t **pp, const uint8_t *p_end)

{

    int val;

    val = get8(pp, p_end);

    if (val < 0)

        return -1;

    h->tid = val;

    *pp += 2;

    val = get16(pp, p_end);

    if (val < 0)

        return -1;

    h->id = val;

    val = get8(pp, p_end);

    if (val < 0)

        return -1;

    h->version = (val >> 1) & 0x1f;

    val = get8(pp, p_end);

    if (val < 0)

        return -1;

    h->sec_num = val;

    val = get8(pp, p_end);

    if (val < 0)

        return -1;

    h->last_sec_num = val;

    return 0;

}

typedef struct {

    uint32_t stream_type;

    enum CodecType codec_type;

    enum CodecID codec_id;

} StreamType;

static const StreamType ISO_types[] = {

    { 0x01, CODEC_TYPE_VIDEO, CODEC_ID_MPEG2VIDEO },

    { 0x02, CODEC_TYPE_VIDEO, CODEC_ID_MPEG2VIDEO },

    { 0x03, CODEC_TYPE_AUDIO,        CODEC_ID_MP3 },

    { 0x04, CODEC_TYPE_AUDIO,        CODEC_ID_MP3 },

    { 0x0f, CODEC_TYPE_AUDIO,        CODEC_ID_AAC },

    { 0x10, CODEC_TYPE_VIDEO,      CODEC_ID_MPEG4 },

    { 0x1b, CODEC_TYPE_VIDEO,       CODEC_ID_H264 },

    { 0xd1, CODEC_TYPE_VIDEO,      CODEC_ID_DIRAC },

    { 0xea, CODEC_TYPE_VIDEO,        CODEC_ID_VC1 },

    { 0 },

};

static const StreamType HDMV_types[] = {

    { 0x81, CODEC_TYPE_AUDIO, CODEC_ID_AC3 },

    { 0x82, CODEC_TYPE_AUDIO, CODEC_ID_DTS },

    { 0 },

};

/* ATSC ? */

static const StreamType MISC_types[] = {

    { 0x81, CODEC_TYPE_AUDIO,   CODEC_ID_AC3 },

    { 0x8a, CODEC_TYPE_AUDIO,   CODEC_ID_DTS },

    {0x100, CODEC_TYPE_SUBTITLE, CODEC_ID_DVB_SUBTITLE }, // demuxer internal

    { 0 },

};

static const StreamType REGD_types[] = {

    { MKTAG('d','r','a','c'), CODEC_TYPE_VIDEO, CODEC_ID_DIRAC },

    { MKTAG('A','C','-','3'), CODEC_TYPE_AUDIO,   CODEC_ID_AC3 },

    { 0 },

};

/* descriptor present */

static const StreamType DESC_types[] = {

    { 0x6a, CODEC_TYPE_AUDIO,             CODEC_ID_AC3 }, /* AC-3 descriptor */

    { 0x7a, CODEC_TYPE_AUDIO,             CODEC_ID_AC3 },

    { 0x7b, CODEC_TYPE_AUDIO,             CODEC_ID_DTS },

    { 0x59, CODEC_TYPE_SUBTITLE, CODEC_ID_DVB_SUBTITLE }, /* subtitling descriptor */

};

static void mpegts_find_stream_type(AVStream *st,

                                    uint32_t stream_type, const StreamType *types)

{

    for (; types->stream_type; types++) {

        if (stream_type == types->stream_type) {

            st->codec->codec_type = types->codec_type;

            st->codec->codec_id   = types->codec_id;

            return;

        }

    }

}

static AVStream *new_pes_av_stream(PESContext *pes, uint32_t prog_reg_desc)

{

    AVStream *st = av_new_stream(pes->stream, pes->pid);

    if (!st)

        return NULL;

    av_set_pts_info(st, 33, 1, 90000);

    st->priv_data = pes;

    st->codec->codec_type = CODEC_TYPE_DATA;

    st->codec->codec_id   = CODEC_ID_PROBE;

    st->need_parsing = AVSTREAM_PARSE_FULL;

    pes->st = st;

    dprintf(pes->stream, "stream_type=%x pid=%x prog_reg_desc=%.4s\n",

            pes->stream_type, pes->pid, (char*)&prog_reg_desc);

        mpegts_find_stream_type(st, pes->stream_type, ISO_types);

        if (prog_reg_desc == AV_RL32("HDMV") &&

            st->codec->codec_id == CODEC_ID_PROBE)

            mpegts_find_stream_type(st, pes->stream_type, HDMV_types);

        if (st->codec->codec_id == CODEC_ID_PROBE)

            mpegts_find_stream_type(st, pes->stream_type, MISC_types);

    return st;

}

static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)

{

    MpegTSContext *ts = filter->u.section_filter.opaque;

    SectionHeader h1, *h = &h1;

    PESContext *pes;

    AVStream *st;

    const uint8_t *p, *p_end, *desc_list_end, *desc_end;

    int program_info_length, pcr_pid, pid, stream_type;

    int desc_list_len, desc_len, desc_tag;

    int comp_page, anc_page;

    char language[4];

    uint32_t prog_reg_desc = 0; /* registration descriptor */

    uint32_t reg_desc; /* registration descriptor */

#ifdef DEBUG

    dprintf(ts->stream, "PMT: len %i\n", section_len);

    av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);

#endif

    p_end = section + section_len - 4;

    p = section;

    if (parse_section_header(h, &p, p_end) < 0)

        return;

    dprintf(ts->stream, "sid=0x%x sec_num=%d/%d\n",

           h->id, h->sec_num, h->last_sec_num);

    if (h->tid != PMT_TID)

        return;

    clear_program(ts, h->id);

    pcr_pid = get16(&p, p_end) & 0x1fff;

    if (pcr_pid < 0)

        return;

    add_pid_to_pmt(ts, h->id, pcr_pid);

    dprintf(ts->stream, "pcr_pid=0x%x\n", pcr_pid);

    program_info_length = get16(&p, p_end) & 0xfff;

    if (program_info_length < 0)

        return;

    while(program_info_length >= 2) {

        uint8_t tag, len;

        tag = get8(&p, p_end);

        len = get8(&p, p_end);

        if(len > program_info_length - 2)

            //something else is broken, exit the program_descriptors_loop

            break;

        program_info_length -= len + 2;

        if(tag == 0x05 && len >= 4) { // registration descriptor

            prog_reg_desc = bytestream_get_le32(&p);

            len -= 4;

        }

        p += len;

    }

    p += program_info_length;

    if (p >= p_end)

        return;

    for(;;) {

        st = 0;

        stream_type = get8(&p, p_end);

        if (stream_type < 0)

            break;

        pid = get16(&p, p_end) & 0x1fff;

        if (pid < 0)

            break;

        /* now create ffmpeg stream */

        if (ts->pids[pid] && ts->pids[pid]->type == MPEGTS_PES) {

            pes = ts->pids[pid]->u.pes_filter.opaque;

            st = pes->st;

        } else {

            if (ts->pids[pid]) mpegts_close_filter(ts, ts->pids[pid]); //wrongly added sdt filter probably

            pes = add_pes_stream(ts, pid, pcr_pid, stream_type);

            if (pes)

                st = new_pes_av_stream(pes, prog_reg_desc);

        }

        if (!st)

            return;

        add_pid_to_pmt(ts, h->id, pid);

        av_program_add_stream_index(ts->stream, h->id, st->index);

        desc_list_len = get16(&p, p_end) & 0xfff;

        if (desc_list_len < 0)

            break;

        desc_list_end = p + desc_list_len;

        if (desc_list_end > p_end)

            break;

        for(;;) {

            desc_tag = get8(&p, desc_list_end);

            if (desc_tag < 0)

                break;

            desc_len = get8(&p, desc_list_end);

            if (desc_len < 0)

                break;

            desc_end = p + desc_len;

            if (desc_end > desc_list_end)

                break;

            dprintf(ts->stream, "tag: 0x%02x len=%d\n",

                   desc_tag, desc_len);

            if (st->codec->codec_id == CODEC_ID_PROBE &&

                stream_type == STREAM_TYPE_PRIVATE_DATA)

                mpegts_find_stream_type(st, desc_tag, DESC_types);

            switch(desc_tag) {

            case 0x59: /* subtitling descriptor */

                language[0] = get8(&p, desc_end);

                language[1] = get8(&p, desc_end);

                language[2] = get8(&p, desc_end);

                language[3] = 0;

                get8(&p, desc_end);

                comp_page = get16(&p, desc_end);

                anc_page = get16(&p, desc_end);

                st->codec->sub_id = (anc_page << 16) | comp_page;

                av_metadata_set(&st->metadata, "language", language);

                break;

            case 0x0a: /* ISO 639 language descriptor */

                language[0] = get8(&p, desc_end);

                language[1] = get8(&p, desc_end);

                language[2] = get8(&p, desc_end);

                language[3] = 0;

                av_metadata_set(&st->metadata, "language", language);

                break;

            case 0x05: /* registration descriptor */

                reg_desc = bytestream_get_le32(&p);

                if (st->codec->codec_id == CODEC_ID_PROBE &&

                    stream_type == STREAM_TYPE_PRIVATE_DATA)

                    mpegts_find_stream_type(st, reg_desc, REGD_types);

                break;

            default:

                break;

            }

            p = desc_end;

        }

        p = desc_list_end;

    }

    /* all parameters are there */

    ts->stop_parse++;

    mpegts_close_filter(ts, filter);

}

static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)

{

    MpegTSContext *ts = filter->u.section_filter.opaque;

    SectionHeader h1, *h = &h1;

    const uint8_t *p, *p_end;

    int sid, pmt_pid;

#ifdef DEBUG

    dprintf(ts->stream, "PAT:\n");

    av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);

#endif

    p_end = section + section_len - 4;

    p = section;

    if (parse_section_header(h, &p, p_end) < 0)

        return;

    if (h->tid != PAT_TID)

        return;

    clear_programs(ts);

    for(;;) {

        sid = get16(&p, p_end);

        if (sid < 0)

            break;

        pmt_pid = get16(&p, p_end) & 0x1fff;

        if (pmt_pid < 0)

            break;

        dprintf(ts->stream, "sid=0x%x pid=0x%x\n", sid, pmt_pid);

        if (sid == 0x0000) {

            /* NIT info */

        } else {

            av_new_program(ts->stream, sid);

            ts->stop_parse--;

            mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);

            add_pat_entry(ts, sid);

            add_pid_to_pmt(ts, sid, 0); //add pat pid to program

            add_pid_to_pmt(ts, sid, pmt_pid);

        }

    }

    /* not found */

    ts->stop_parse++;

    mpegts_close_filter(ts, filter);

}

static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)

{

    MpegTSContext *ts = filter->u.section_filter.opaque;

    SectionHeader h1, *h = &h1;

    const uint8_t *p, *p_end, *desc_list_end, *desc_end;

    int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type;

    char *name, *provider_name;

#ifdef DEBUG

    dprintf(ts->stream, "SDT:\n");

    av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);

#endif

    p_end = section + section_len - 4;

    p = section;

    if (parse_section_header(h, &p, p_end) < 0)

        return;

    if (h->tid != SDT_TID)

        return;

    onid = get16(&p, p_end);

    if (onid < 0)

        return;

    val = get8(&p, p_end);

    if (val < 0)

        return;

    for(;;) {

        sid = get16(&p, p_end);

        if (sid < 0)

            break;

        val = get8(&p, p_end);

        if (val < 0)

            break;

        desc_list_len = get16(&p, p_end) & 0xfff;

        if (desc_list_len < 0)

            break;

        desc_list_end = p + desc_list_len;

        if (desc_list_end > p_end)

            break;

        for(;;) {

            desc_tag = get8(&p, desc_list_end);

            if (desc_tag < 0)

                break;

            desc_len = get8(&p, desc_list_end);

            desc_end = p + desc_len;

            if (desc_end > desc_list_end)

                break;

            dprintf(ts->stream, "tag: 0x%02x len=%d\n",

                   desc_tag, desc_len);

            switch(desc_tag) {

            case 0x48:

                service_type = get8(&p, p_end);

                if (service_type < 0)

                    break;

                provider_name = getstr8(&p, p_end);

                if (!provider_name)

                    break;

                name = getstr8(&p, p_end);

                if (name) {

                    AVProgram *program = av_new_program(ts->stream, sid);

                    if(program) {

                        av_metadata_set(&program->metadata, "name", name);

                        av_metadata_set(&program->metadata, "provider_name", provider_name);

                    }

                }

                av_free(name);

                av_free(provider_name);

                break;

            default:

                break;

            }

            p = desc_end;

        }

        p = desc_list_end;

    }

}

static int64_t get_pts(const uint8_t *p)

{

    int64_t pts = (int64_t)((p[0] >> 1) & 0x07) << 30;

    pts |= (AV_RB16(p + 1) >> 1) << 15;

    pts |=  AV_RB16(p + 3) >> 1;

    return pts;

}

static void new_pes_packet(PESContext *pes, AVPacket *pkt)

{

    av_init_packet(pkt);

    pkt->destruct = av_destruct_packet;

    pkt->data = pes->buffer;

    pkt->size = pes->data_index;

    memset(pkt->data+pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);

    pkt->stream_index = pes->st->index;

    pkt->pts = pes->pts;

    pkt->dts = pes->dts;

    /* store position of first TS packet of this PES packet */

    pkt->pos = pes->ts_packet_pos;

    /* reset pts values */

    pes->pts = AV_NOPTS_VALUE;

    pes->dts = AV_NOPTS_VALUE;

    pes->buffer = NULL;

    pes->data_index = 0;

}

/* return non zero if a packet could be constructed */

static int mpegts_push_data(MpegTSFilter *filter,

                            const uint8_t *buf, int buf_size, int is_start,

                            int64_t pos)

{

    PESContext *pes = filter->u.pes_filter.opaque;

    MpegTSContext *ts = pes->ts;

    const uint8_t *p;

    int len, code;

    if(!ts->pkt)

        return 0;

    if (is_start) {

        if (pes->state == MPEGTS_PAYLOAD && pes->data_index > 0) {

            new_pes_packet(pes, ts->pkt);

            ts->stop_parse = 1;

        }

        pes->state = MPEGTS_HEADER;

        pes->data_index = 0;

        pes->ts_packet_pos = pos;

    }

    p = buf;

    while (buf_size > 0) {

        switch(pes->state) {

        case MPEGTS_HEADER:

            len = PES_START_SIZE - pes->data_index;

            if (len > buf_size)

                len = buf_size;

            memcpy(pes->header + pes->data_index, p, len);

            pes->data_index += len;

            p += len;

            buf_size -= len;

            if (pes->data_index == PES_START_SIZE) {

                /* we got all the PES or section header. We can now

                   decide */

#if 0

                av_hex_dump_log(pes->stream, AV_LOG_DEBUG, pes->header, pes->data_index);

#endif

                if (pes->header[0] == 0x00 && pes->header[1] == 0x00 &&

                    pes->header[2] == 0x01) {

                    /* it must be an mpeg2 PES stream */

                    code = pes->header[3] | 0x100;

                    if (!pes->st || pes->st->discard == AVDISCARD_ALL ||

                        !((code >= 0x1c0 && code <= 0x1df) ||

                          (code >= 0x1e0 && code <= 0x1ef) ||

                          (code == 0x1bd) || (code == 0x1fd)))

                        goto skip;

                    pes->state = MPEGTS_PESHEADER_FILL;

                    pes->total_size = AV_RB16(pes->header + 4);

                    /* NOTE: a zero total size means the PES size is

                       unbounded */

                    pes->pes_header_size = pes->header[8] + 9;

                } else {

                    /* otherwise, it should be a table */

                    /* skip packet */

                skip:

                    pes->state = MPEGTS_SKIP;

                    continue;

                }

            }

            break;

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

            /* PES packing parsing */

        case MPEGTS_PESHEADER_FILL:

            len = pes->pes_header_size - pes->data_index;

            if (len < 0)

                return -1;

            if (len > buf_size)

                len = buf_size;

            memcpy(pes->header + pes->data_index, p, len);

            pes->data_index += len;

            p += len;

            buf_size -= len;

            if (pes->data_index == pes->pes_header_size) {

                const uint8_t *r;

                unsigned int flags;

                flags = pes->header[7];

                r = pes->header + 9;

                pes->pts = AV_NOPTS_VALUE;

                pes->dts = AV_NOPTS_VALUE;

                if ((flags & 0xc0) == 0x80) {

                    pes->dts = pes->pts = get_pts(r);

                    r += 5;

                } else if ((flags & 0xc0) == 0xc0) {

                    pes->pts = get_pts(r);

                    r += 5;

                    pes->dts = get_pts(r);

                    r += 5;

                }

                if (pes->total_size > pes->data_index - 6)

                    pes->total_size -= pes->data_index - 6;

                else

                    pes->total_size = MAX_PES_PAYLOAD;

                /* allocate pes buffer */

                pes->buffer = av_malloc(pes->total_size+FF_INPUT_BUFFER_PADDING_SIZE);

                if (!pes->buffer)

                    return AVERROR(ENOMEM);

                /* we got the full header. We parse it and get the payload */

                pes->state = MPEGTS_PAYLOAD;

                pes->data_index = 0;

            }

            break;

        case MPEGTS_PAYLOAD:

            if (buf_size > 0) {

                if (pes->data_index+buf_size > pes->total_size) {

                    new_pes_packet(pes, ts->pkt);

                    pes->total_size = MAX_PES_PAYLOAD;

                    pes->buffer = av_malloc(pes->total_size+FF_INPUT_BUFFER_PADDING_SIZE);

                    if (!pes->buffer)

                        return AVERROR(ENOMEM);

                    ts->stop_parse = 1;

                }

                memcpy(pes->buffer+pes->data_index, p, buf_size);

                pes->data_index += buf_size;

            }

            buf_size = 0;

            break;

        case MPEGTS_SKIP:

            buf_size = 0;

            break;

        }

    }

    return 0;

}

static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid, int stream_type)

{

    MpegTSFilter *tss;

    PESContext *pes;

    /* if no pid found, then add a pid context */

    pes = av_mallocz(sizeof(PESContext));

    if (!pes)

        return 0;

    pes->ts = ts;

    pes->stream = ts->stream;

    pes->pid = pid;

    pes->pcr_pid = pcr_pid;

    pes->stream_type = stream_type;

    tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes);

    if (!tss) {

        av_free(pes);

        return 0;

    }

    return pes;

}

/* handle one TS packet */

static int handle_packet(MpegTSContext *ts, const uint8_t *packet)

{

    AVFormatContext *s = ts->stream;

    MpegTSFilter *tss;

    int len, pid, cc, cc_ok, afc, is_start;

    const uint8_t *p, *p_end;

    int64_t pos;

    pid = AV_RB16(packet + 1) & 0x1fff;

    if(pid && discard_pid(ts, pid))

        return 0;

    is_start = packet[1] & 0x40;

    tss = ts->pids[pid];

    if (ts->auto_guess && tss == NULL && is_start) {

        add_pes_stream(ts, pid, -1, 0);

        tss = ts->pids[pid];

    }

    if (!tss)

        return 0;

    /* continuity check (currently not used) */

    cc = (packet[3] & 0xf);

    cc_ok = (tss->last_cc < 0) || ((((tss->last_cc + 1) & 0x0f) == cc));

    tss->last_cc = cc;

    /* skip adaptation field */

    afc = (packet[3] >> 4) & 3;

    p = packet + 4;

    if (afc == 0) /* reserved value */

        return 0;

    if (afc == 2) /* adaptation field only */

        return 0;

    if (afc == 3) {

        /* skip adapation field */

        p += p[0] + 1;

    }

    /* if past the end of packet, ignore */

    p_end = packet + TS_PACKET_SIZE;

    if (p >= p_end)

        return 0;

    pos = url_ftell(ts->stream->pb);

    ts->pos47= pos % ts->raw_packet_size;

    if (tss->type == MPEGTS_SECTION) {

        if (is_start) {

            /* pointer field present */

            len = *p++;

            if (p + len > p_end)

                return 0;

            if (len && cc_ok) {

                /* write remaining section bytes */

                write_section_data(s, tss,

                                   p, len, 0);

                /* check whether filter has been closed */

                if (!ts->pids[pid])

                    return 0;

            }

            p += len;

            if (p < p_end) {

                write_section_data(s, tss,

                                   p, p_end - p, 1);

            }

        } else {

            if (cc_ok) {

                write_section_data(s, tss,

                                   p, p_end - p, 0);

            }

        }

    } else {

        int ret;

        // Note: The position here points actually behind the current packet.

        if ((ret = tss->u.pes_filter.pes_cb(tss, p, p_end - p, is_start,

                                            pos - ts->raw_packet_size)) < 0)

            return ret;

    }

    return 0;

}

/* XXX: try to find a better synchro over several packets (use

   get_packet_size() ?) */

static int mpegts_resync(ByteIOContext *pb)

{

    int c, i;

    for(i = 0;i < MAX_RESYNC_SIZE; i++) {

        c = url_fgetc(pb);

        if (c < 0)

            return -1;

        if (c == 0x47) {

            url_fseek(pb, -1, SEEK_CUR);

            return 0;

        }

    }

    /* no sync found */

    return -1;

}

/* return -1 if error or EOF. Return 0 if OK. */

static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size)

{

    int skip, len;

    for(;;) {

        len = get_buffer(pb, buf, TS_PACKET_SIZE);

        if (len != TS_PACKET_SIZE)

            return AVERROR(EIO);

        /* check paquet sync byte */

        if (buf[0] != 0x47) {

            /* find a new packet start */

            url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR);

            if (mpegts_resync(pb) < 0)

                return AVERROR_INVALIDDATA;

            else

                continue;

        } else {

            skip = raw_packet_size - TS_PACKET_SIZE;

            if (skip > 0)

                url_fskip(pb, skip);

            break;

        }

    }

    return 0;

}

static int handle_packets(MpegTSContext *ts, int nb_packets)

{

    AVFormatContext *s = ts->stream;

    ByteIOContext *pb = s->pb;

    uint8_t packet[TS_PACKET_SIZE];

    int packet_num, ret;

    ts->stop_parse = 0;

    packet_num = 0;

    for(;;) {

        if (ts->stop_parse>0)

            break;

        packet_num++;

        if (nb_packets != 0 && packet_num >= nb_packets)

            break;

        ret = read_packet(pb, packet, ts->raw_packet_size);

        if (ret != 0)

            return ret;

        ret = handle_packet(ts, packet);

        if (ret != 0)

            return ret;

    }

    return 0;

}

static int mpegts_probe(AVProbeData *p)

{

#if 1

    const int size= p->buf_size;

    int score, fec_score, dvhs_score;

    int check_count= size / TS_FEC_PACKET_SIZE;

#define CHECK_COUNT 10

    if (check_count < CHECK_COUNT)

        return -1;

    score     = analyze(p->buf, TS_PACKET_SIZE     *check_count, TS_PACKET_SIZE     , NULL)*CHECK_COUNT/check_count;

    dvhs_score= analyze(p->buf, TS_DVHS_PACKET_SIZE*check_count, TS_DVHS_PACKET_SIZE, NULL)*CHECK_COUNT/check_count;

    fec_score = analyze(p->buf, TS_FEC_PACKET_SIZE *check_count, TS_FEC_PACKET_SIZE , NULL)*CHECK_COUNT/check_count;

//    av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);

// we need a clear definition for the returned score otherwise things will become messy sooner or later

    if     (score > fec_score && score > dvhs_score && score > 6) return AVPROBE_SCORE_MAX + score     - CHECK_COUNT;

    else if(dvhs_score > score && dvhs_score > fec_score && dvhs_score > 6) return AVPROBE_SCORE_MAX + dvhs_score  - CHECK_COUNT;

    else if(                 fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;

    else                                    return -1;

#else

    /* only use the extension for safer guess */

    if (match_ext(p->filename, "ts"))

        return AVPROBE_SCORE_MAX;

    else

        return 0;

#endif

}

/* return the 90kHz PCR and the extension for the 27MHz PCR. return

   (-1) if not available */

static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,

                     const uint8_t *packet)

{

    int afc, len, flags;

    const uint8_t *p;

    unsigned int v;

    afc = (packet[3] >> 4) & 3;

    if (afc <= 1)

        return -1;

    p = packet + 4;

    len = p[0];

    p++;

    if (len == 0)

        return -1;

    flags = *p++;

    len--;

    if (!(flags & 0x10))

        return -1;

    if (len < 6)

        return -1;

    v = AV_RB32(p);

    *ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);

    *ppcr_low = ((p[4] & 1) << 8) | p[5];

    return 0;

}

static int mpegts_read_header(AVFormatContext *s,

                              AVFormatParameters *ap)

{

    MpegTSContext *ts = s->priv_data;

    ByteIOContext *pb = s->pb;

    uint8_t buf[5*1024];

    int len;

    int64_t pos;

    if (ap) {

        ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;

        if(ap->mpeg2ts_raw){

            av_log(s, AV_LOG_ERROR, "use mpegtsraw_demuxer!\n");

            return -1;

        }

    }

    /* read the first 1024 bytes to get packet size */

    pos = url_ftell(pb);

    len = get_buffer(pb, buf, sizeof(buf));

    if (len != sizeof(buf))

        goto fail;

    ts->raw_packet_size = get_packet_size(buf, sizeof(buf));

    if (ts->raw_packet_size <= 0)

        goto fail;

    ts->stream = s;

    ts->auto_guess = 0;

    if (s->iformat == &mpegts_demuxer) {

        /* normal demux */

        /* first do a scaning to get all the services */

        url_fseek(pb, pos, SEEK_SET);

        mpegts_open_section_filter(ts, SDT_PID, sdt_cb, ts, 1);

        mpegts_open_section_filter(ts, PAT_PID, pat_cb, ts, 1);

        handle_packets(ts, s->probesize);

        /* if could not find service, enable auto_guess */

        ts->auto_guess = 1;

        dprintf(ts->stream, "tuning done\n");

        s->ctx_flags |= AVFMTCTX_NOHEADER;

    } else {

        AVStream *st;

        int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;

        int64_t pcrs[2], pcr_h;

        int packet_count[2];

        uint8_t packet[TS_PACKET_SIZE];

        /* only read packets */

        st = av_new_stream(s, 0);

        if (!st)

            goto fail;

        av_set_pts_info(st, 60, 1, 27000000);

        st->codec->codec_type = CODEC_TYPE_DATA;

        st->codec->codec_id = CODEC_ID_MPEG2TS;

        /* we iterate until we find two PCRs to estimate the bitrate */

        pcr_pid = -1;

        nb_pcrs = 0;

        nb_packets = 0;

        for(;;) {

            ret = read_packet(s->pb, packet, ts->raw_packet_size);

            if (ret < 0)

                return -1;

            pid = AV_RB16(packet + 1) & 0x1fff;

            if ((pcr_pid == -1 || pcr_pid == pid) &&

                parse_pcr(&pcr_h, &pcr_l, packet) == 0) {

                pcr_pid = pid;

                packet_count[nb_pcrs] = nb_packets;

                pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;

                nb_pcrs++;

                if (nb_pcrs >= 2)

                    break;

            }

            nb_packets++;

        }

        /* NOTE1: the bitrate is computed without the FEC */

        /* NOTE2: it is only the bitrate of the start of the stream */

        ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);

        ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];

        s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;

        st->codec->bit_rate = s->bit_rate;

        st->start_time = ts->cur_pcr;

#if 0

        av_log(ts->stream, AV_LOG_DEBUG, "start=%0.3f pcr=%0.3f incr=%d\n",

               st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);

#endif

    }

    url_fseek(pb, pos, SEEK_SET);

    return 0;

 fail:

    return -1;

}

#define MAX_PACKET_READAHEAD ((128 * 1024) / 188)

static int mpegts_raw_read_packet(AVFormatContext *s,

                                  AVPacket *pkt)

{

    MpegTSContext *ts = s->priv_data;

    int ret, i;

    int64_t pcr_h, next_pcr_h, pos;

    int pcr_l, next_pcr_l;

    uint8_t pcr_buf[12];