FFmpeg: libavformat/mpegtsenc.c Source File

00001 /*
00002  * MPEG2 transport stream (aka DVB) muxer
00003  * Copyright (c) 2003 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/bswap.h"
00023 #include "libavutil/crc.h"
00024 #include "libavcodec/mpegvideo.h"
00025 #include "avformat.h"
00026 #include "internal.h"
00027 #include "mpegts.h"
00028 #include "adts.h"
00029 
00030 /* write DVB SI sections */
00031 
00032 /*********************************************/
00033 /* mpegts section writer */
00034 
00035 typedef struct MpegTSSection {
00036     int pid;
00037     int cc;
00038     void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
00039     void *opaque;
00040 } MpegTSSection;
00041 
00042 typedef struct MpegTSService {
00043     MpegTSSection pmt; /* MPEG2 pmt table context */
00044     int sid;           /* service ID */
00045     char *name;
00046     char *provider_name;
00047     int pcr_pid;
00048     int pcr_packet_count;
00049     int pcr_packet_period;
00050 } MpegTSService;
00051 
00052 typedef struct MpegTSWrite {
00053     MpegTSSection pat; /* MPEG2 pat table */
00054     MpegTSSection sdt; /* MPEG2 sdt table context */
00055     MpegTSService **services;
00056     int sdt_packet_count;
00057     int sdt_packet_period;
00058     int pat_packet_count;
00059     int pat_packet_period;
00060     int nb_services;
00061     int onid;
00062     int tsid;
00063     uint64_t cur_pcr;
00064     int mux_rate; 
00065 } MpegTSWrite;
00066 
00067 /* NOTE: 4 bytes must be left at the end for the crc32 */
00068 static void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)
00069 {
00070     MpegTSWrite *ts = ((AVFormatContext*)s->opaque)->priv_data;
00071     unsigned int crc;
00072     unsigned char packet[TS_PACKET_SIZE];
00073     const unsigned char *buf_ptr;
00074     unsigned char *q;
00075     int first, b, len1, left;
00076 
00077     crc = bswap_32(av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1, buf, len - 4));
00078     buf[len - 4] = (crc >> 24) & 0xff;
00079     buf[len - 3] = (crc >> 16) & 0xff;
00080     buf[len - 2] = (crc >> 8) & 0xff;
00081     buf[len - 1] = (crc) & 0xff;
00082 
00083     /* send each packet */
00084     buf_ptr = buf;
00085     while (len > 0) {
00086         first = (buf == buf_ptr);
00087         q = packet;
00088         *q++ = 0x47;
00089         b = (s->pid >> 8);
00090         if (first)
00091             b |= 0x40;
00092         *q++ = b;
00093         *q++ = s->pid;
00094         s->cc = (s->cc + 1) & 0xf;
00095         *q++ = 0x10 | s->cc;
00096         if (first)
00097             *q++ = 0; /* 0 offset */
00098         len1 = TS_PACKET_SIZE - (q - packet);
00099         if (len1 > len)
00100             len1 = len;
00101         memcpy(q, buf_ptr, len1);
00102         q += len1;
00103         /* add known padding data */
00104         left = TS_PACKET_SIZE - (q - packet);
00105         if (left > 0)
00106             memset(q, 0xff, left);
00107 
00108         s->write_packet(s, packet);
00109 
00110         buf_ptr += len1;
00111         len -= len1;
00112 
00113         ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
00114     }
00115 }
00116 
00117 static inline void put16(uint8_t **q_ptr, int val)
00118 {
00119     uint8_t *q;
00120     q = *q_ptr;
00121     *q++ = val >> 8;
00122     *q++ = val;
00123     *q_ptr = q;
00124 }
00125 
00126 static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
00127                           int version, int sec_num, int last_sec_num,
00128                           uint8_t *buf, int len)
00129 {
00130     uint8_t section[1024], *q;
00131     unsigned int tot_len;
00132 
00133     tot_len = 3 + 5 + len + 4;
00134     /* check if not too big */
00135     if (tot_len > 1024)
00136         return -1;
00137 
00138     q = section;
00139     *q++ = tid;
00140     put16(&q, 0xb000 | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
00141     put16(&q, id);
00142     *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
00143     *q++ = sec_num;
00144     *q++ = last_sec_num;
00145     memcpy(q, buf, len);
00146 
00147     mpegts_write_section(s, section, tot_len);
00148     return 0;
00149 }
00150 
00151 /*********************************************/
00152 /* mpegts writer */
00153 
00154 #define DEFAULT_PMT_START_PID   0x1000
00155 #define DEFAULT_START_PID       0x0100
00156 #define DEFAULT_PROVIDER_NAME   "FFmpeg"
00157 #define DEFAULT_SERVICE_NAME    "Service01"
00158 
00159 /* default network id, transport stream and service identifiers */
00160 #define DEFAULT_ONID            0x0001
00161 #define DEFAULT_TSID            0x0001
00162 #define DEFAULT_SID             0x0001
00163 
00164 /* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
00165 #define DEFAULT_PES_HEADER_FREQ 16
00166 #define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
00167 
00168 /* we retransmit the SI info at this rate */
00169 #define SDT_RETRANS_TIME 500
00170 #define PAT_RETRANS_TIME 100
00171 #define PCR_RETRANS_TIME 20
00172 
00173 typedef struct MpegTSWriteStream {
00174     struct MpegTSService *service;
00175     int pid; /* stream associated pid */
00176     int cc;
00177     int payload_index;
00178     int first_pts_check; 
00179     int64_t payload_pts;
00180     int64_t payload_dts;
00181     uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
00182     ADTSContext *adts;
00183 } MpegTSWriteStream;
00184 
00185 static void mpegts_write_pat(AVFormatContext *s)
00186 {
00187     MpegTSWrite *ts = s->priv_data;
00188     MpegTSService *service;
00189     uint8_t data[1012], *q;
00190     int i;
00191 
00192     q = data;
00193     for(i = 0; i < ts->nb_services; i++) {
00194         service = ts->services[i];
00195         put16(&q, service->sid);
00196         put16(&q, 0xe000 | service->pmt.pid);
00197     }
00198     mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
00199                           data, q - data);
00200 }
00201 
00202 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
00203 {
00204     //    MpegTSWrite *ts = s->priv_data;
00205     uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;
00206     int val, stream_type, i;
00207 
00208     q = data;
00209     put16(&q, 0xe000 | service->pcr_pid);
00210 
00211     program_info_length_ptr = q;
00212     q += 2; /* patched after */
00213 
00214     /* put program info here */
00215 
00216     val = 0xf000 | (q - program_info_length_ptr - 2);
00217     program_info_length_ptr[0] = val >> 8;
00218     program_info_length_ptr[1] = val;
00219 
00220     for(i = 0; i < s->nb_streams; i++) {
00221         AVStream *st = s->streams[i];
00222         MpegTSWriteStream *ts_st = st->priv_data;
00223         AVMetadataTag *lang = av_metadata_get(st->metadata, "language", NULL,0);
00224         switch(st->codec->codec_id) {
00225         case CODEC_ID_MPEG1VIDEO:
00226         case CODEC_ID_MPEG2VIDEO:
00227             stream_type = STREAM_TYPE_VIDEO_MPEG2;
00228             break;
00229         case CODEC_ID_MPEG4:
00230             stream_type = STREAM_TYPE_VIDEO_MPEG4;
00231             break;
00232         case CODEC_ID_H264:
00233             stream_type = STREAM_TYPE_VIDEO_H264;
00234             break;
00235         case CODEC_ID_DIRAC:
00236             stream_type = STREAM_TYPE_VIDEO_DIRAC;
00237             break;
00238         case CODEC_ID_MP2:
00239         case CODEC_ID_MP3:
00240             stream_type = STREAM_TYPE_AUDIO_MPEG1;
00241             break;
00242         case CODEC_ID_AAC:
00243             stream_type = STREAM_TYPE_AUDIO_AAC;
00244             break;
00245         case CODEC_ID_AC3:
00246             stream_type = STREAM_TYPE_AUDIO_AC3;
00247             break;
00248         default:
00249             stream_type = STREAM_TYPE_PRIVATE_DATA;
00250             break;
00251         }
00252         *q++ = stream_type;
00253         put16(&q, 0xe000 | ts_st->pid);
00254         desc_length_ptr = q;
00255         q += 2; /* patched after */
00256 
00257         /* write optional descriptors here */
00258         switch(st->codec->codec_type) {
00259         case AVMEDIA_TYPE_AUDIO:
00260             if (lang && strlen(lang->value) == 3) {
00261                 *q++ = 0x0a; /* ISO 639 language descriptor */
00262                 *q++ = 4;
00263                 *q++ = lang->value[0];
00264                 *q++ = lang->value[1];
00265                 *q++ = lang->value[2];
00266                 *q++ = 0; /* undefined type */
00267             }
00268             break;
00269         case AVMEDIA_TYPE_SUBTITLE:
00270             {
00271                 const char *language;
00272                 language = lang && strlen(lang->value)==3 ? lang->value : "eng";
00273                 *q++ = 0x59;
00274                 *q++ = 8;
00275                 *q++ = language[0];
00276                 *q++ = language[1];
00277                 *q++ = language[2];
00278                 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
00279                 put16(&q, 1); /* page id */
00280                 put16(&q, 1); /* ancillary page id */
00281             }
00282             break;
00283         case AVMEDIA_TYPE_VIDEO:
00284             if (stream_type == STREAM_TYPE_VIDEO_DIRAC) {
00285                 *q++ = 0x05; /*MPEG-2 registration descriptor*/
00286                 *q++ = 4;
00287                 *q++ = 'd';
00288                 *q++ = 'r';
00289                 *q++ = 'a';
00290                 *q++ = 'c';
00291             }
00292             break;
00293         }
00294 
00295         val = 0xf000 | (q - desc_length_ptr - 2);
00296         desc_length_ptr[0] = val >> 8;
00297         desc_length_ptr[1] = val;
00298     }
00299     mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
00300                           data, q - data);
00301 }
00302 
00303 /* NOTE: str == NULL is accepted for an empty string */
00304 static void putstr8(uint8_t **q_ptr, const char *str)
00305 {
00306     uint8_t *q;
00307     int len;
00308 
00309     q = *q_ptr;
00310     if (!str)
00311         len = 0;
00312     else
00313         len = strlen(str);
00314     *q++ = len;
00315     memcpy(q, str, len);
00316     q += len;
00317     *q_ptr = q;
00318 }
00319 
00320 static void mpegts_write_sdt(AVFormatContext *s)
00321 {
00322     MpegTSWrite *ts = s->priv_data;
00323     MpegTSService *service;
00324     uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;
00325     int i, running_status, free_ca_mode, val;
00326 
00327     q = data;
00328     put16(&q, ts->onid);
00329     *q++ = 0xff;
00330     for(i = 0; i < ts->nb_services; i++) {
00331         service = ts->services[i];
00332         put16(&q, service->sid);
00333         *q++ = 0xfc | 0x00; /* currently no EIT info */
00334         desc_list_len_ptr = q;
00335         q += 2;
00336         running_status = 4; /* running */
00337         free_ca_mode = 0;
00338 
00339         /* write only one descriptor for the service name and provider */
00340         *q++ = 0x48;
00341         desc_len_ptr = q;
00342         q++;
00343         *q++ = 0x01; /* digital television service */
00344         putstr8(&q, service->provider_name);
00345         putstr8(&q, service->name);
00346         desc_len_ptr[0] = q - desc_len_ptr - 1;
00347 
00348         /* fill descriptor length */
00349         val = (running_status << 13) | (free_ca_mode << 12) |
00350             (q - desc_list_len_ptr - 2);
00351         desc_list_len_ptr[0] = val >> 8;
00352         desc_list_len_ptr[1] = val;
00353     }
00354     mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
00355                           data, q - data);
00356 }
00357 
00358 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
00359                                          int sid,
00360                                          const char *provider_name,
00361                                          const char *name)
00362 {
00363     MpegTSService *service;
00364 
00365     service = av_mallocz(sizeof(MpegTSService));
00366     if (!service)
00367         return NULL;
00368     service->pmt.pid = DEFAULT_PMT_START_PID + ts->nb_services - 1;
00369     service->sid = sid;
00370     service->provider_name = av_strdup(provider_name);
00371     service->name = av_strdup(name);
00372     service->pcr_pid = 0x1fff;
00373     dynarray_add(&ts->services, &ts->nb_services, service);
00374     return service;
00375 }
00376 
00377 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
00378 {
00379     AVFormatContext *ctx = s->opaque;
00380     put_buffer(ctx->pb, packet, TS_PACKET_SIZE);
00381 }
00382 
00383 static int mpegts_write_header(AVFormatContext *s)
00384 {
00385     MpegTSWrite *ts = s->priv_data;
00386     MpegTSWriteStream *ts_st;
00387     MpegTSService *service;
00388     AVStream *st, *pcr_st = NULL;
00389     AVMetadataTag *title;
00390     int i;
00391     const char *service_name;
00392 
00393     ts->tsid = DEFAULT_TSID;
00394     ts->onid = DEFAULT_ONID;
00395     /* allocate a single DVB service */
00396     title = av_metadata_get(s->metadata, "title", NULL, 0);
00397     service_name = title ? title->value : DEFAULT_SERVICE_NAME;
00398     service = mpegts_add_service(ts, DEFAULT_SID,
00399                                  DEFAULT_PROVIDER_NAME, service_name);
00400     service->pmt.write_packet = section_write_packet;
00401     service->pmt.opaque = s;
00402     service->pmt.cc = 15;
00403 
00404     ts->pat.pid = PAT_PID;
00405     ts->pat.cc = 15; // Initialize at 15 so that it wraps and be equal to 0 for the first packet we write
00406     ts->pat.write_packet = section_write_packet;
00407     ts->pat.opaque = s;
00408 
00409     ts->sdt.pid = SDT_PID;
00410     ts->sdt.cc = 15;
00411     ts->sdt.write_packet = section_write_packet;
00412     ts->sdt.opaque = s;
00413 
00414     /* assign pids to each stream */
00415     for(i = 0;i < s->nb_streams; i++) {
00416         st = s->streams[i];
00417         ts_st = av_mallocz(sizeof(MpegTSWriteStream));
00418         if (!ts_st)
00419             goto fail;
00420         st->priv_data = ts_st;
00421         ts_st->service = service;
00422         ts_st->pid = DEFAULT_START_PID + i;
00423         ts_st->payload_pts = AV_NOPTS_VALUE;
00424         ts_st->payload_dts = AV_NOPTS_VALUE;
00425         ts_st->first_pts_check = 1;
00426         ts_st->cc = 15;
00427         /* update PCR pid by using the first video stream */
00428         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
00429             service->pcr_pid == 0x1fff) {
00430             service->pcr_pid = ts_st->pid;
00431             pcr_st = st;
00432         }
00433         if (st->codec->codec_id == CODEC_ID_AAC &&
00434             st->codec->extradata_size > 0) {
00435             ts_st->adts = av_mallocz(sizeof(*ts_st->adts));
00436             if (!ts_st->adts)
00437                 return AVERROR(ENOMEM);
00438             if (ff_adts_decode_extradata(s, ts_st->adts, st->codec->extradata,
00439                                          st->codec->extradata_size) < 0)
00440                 return -1;
00441         }
00442     }
00443 
00444     /* if no video stream, use the first stream as PCR */
00445     if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
00446         pcr_st = s->streams[0];
00447         ts_st = pcr_st->priv_data;
00448         service->pcr_pid = ts_st->pid;
00449     }
00450 
00451     ts->mux_rate = s->mux_rate ? s->mux_rate : 1;
00452 
00453     if (ts->mux_rate > 1) {
00454         service->pcr_packet_period = (ts->mux_rate * PCR_RETRANS_TIME) /
00455             (TS_PACKET_SIZE * 8 * 1000);
00456         ts->sdt_packet_period      = (ts->mux_rate * SDT_RETRANS_TIME) /
00457             (TS_PACKET_SIZE * 8 * 1000);
00458         ts->pat_packet_period      = (ts->mux_rate * PAT_RETRANS_TIME) /
00459             (TS_PACKET_SIZE * 8 * 1000);
00460 
00461         ts->cur_pcr = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
00462     } else {
00463         /* Arbitrary values, PAT/PMT could be written on key frames */
00464         ts->sdt_packet_period = 200;
00465         ts->pat_packet_period = 40;
00466         if (pcr_st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
00467             if (!pcr_st->codec->frame_size) {
00468                 av_log(s, AV_LOG_WARNING, "frame size not set\n");
00469                 service->pcr_packet_period =
00470                     pcr_st->codec->sample_rate/(10*512);
00471             } else {
00472                 service->pcr_packet_period =
00473                     pcr_st->codec->sample_rate/(10*pcr_st->codec->frame_size);
00474             }
00475         } else {
00476             // max delta PCR 0.1s
00477             service->pcr_packet_period =
00478                 pcr_st->codec->time_base.den/(10*pcr_st->codec->time_base.num);
00479         }
00480     }
00481 
00482     // output a PCR as soon as possible
00483     service->pcr_packet_count = service->pcr_packet_period;
00484     ts->pat_packet_count = ts->pat_packet_period-1;
00485     ts->sdt_packet_count = ts->sdt_packet_period-1;
00486 
00487     av_log(s, AV_LOG_INFO,
00488            "muxrate %d bps, pcr every %d pkts, "
00489            "sdt every %d, pat/pmt every %d pkts\n",
00490            ts->mux_rate, service->pcr_packet_period,
00491            ts->sdt_packet_period, ts->pat_packet_period);
00492 
00493 
00494     put_flush_packet(s->pb);
00495 
00496     return 0;
00497 
00498  fail:
00499     for(i = 0;i < s->nb_streams; i++) {
00500         st = s->streams[i];
00501         av_free(st->priv_data);
00502     }
00503     return -1;
00504 }
00505 
00506 /* send SDT, PAT and PMT tables regulary */
00507 static void retransmit_si_info(AVFormatContext *s)
00508 {
00509     MpegTSWrite *ts = s->priv_data;
00510     int i;
00511 
00512     if (++ts->sdt_packet_count == ts->sdt_packet_period) {
00513         ts->sdt_packet_count = 0;
00514         mpegts_write_sdt(s);
00515     }
00516     if (++ts->pat_packet_count == ts->pat_packet_period) {
00517         ts->pat_packet_count = 0;
00518         mpegts_write_pat(s);
00519         for(i = 0; i < ts->nb_services; i++) {
00520             mpegts_write_pmt(s, ts->services[i]);
00521         }
00522     }
00523 }
00524 
00525 /* Write a single null transport stream packet */
00526 static void mpegts_insert_null_packet(AVFormatContext *s)
00527 {
00528     MpegTSWrite *ts = s->priv_data;
00529     uint8_t *q;
00530     uint8_t buf[TS_PACKET_SIZE];
00531 
00532     q = buf;
00533     *q++ = 0x47;
00534     *q++ = 0x00 | 0x1f;
00535     *q++ = 0xff;
00536     *q++ = 0x10;
00537     memset(q, 0x0FF, TS_PACKET_SIZE - (q - buf));
00538     put_buffer(s->pb, buf, TS_PACKET_SIZE);
00539     ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
00540 }
00541 
00542 /* Write a single transport stream packet with a PCR and no payload */
00543 static void mpegts_insert_pcr_only(AVFormatContext *s, AVStream *st)
00544 {
00545     MpegTSWrite *ts = s->priv_data;
00546     MpegTSWriteStream *ts_st = st->priv_data;
00547     uint8_t *q;
00548     uint64_t pcr = ts->cur_pcr;
00549     uint8_t buf[TS_PACKET_SIZE];
00550 
00551     q = buf;
00552     *q++ = 0x47;
00553     *q++ = ts_st->pid >> 8;
00554     *q++ = ts_st->pid;
00555     *q++ = 0x20 | ts_st->cc;   /* Adaptation only */
00556     /* Continuity Count field does not increment (see 13818-1 section 2.4.3.3) */
00557     *q++ = TS_PACKET_SIZE - 5; /* Adaptation Field Length */
00558     *q++ = 0x10;               /* Adaptation flags: PCR present */
00559 
00560     /* PCR coded into 6 bytes */
00561     *q++ = pcr >> 25;
00562     *q++ = pcr >> 17;
00563     *q++ = pcr >> 9;
00564     *q++ = pcr >> 1;
00565     *q++ = (pcr & 1) << 7;
00566     *q++ = 0;
00567 
00568     /* stuffing bytes */
00569     memset(q, 0xFF, TS_PACKET_SIZE - (q - buf));
00570     put_buffer(s->pb, buf, TS_PACKET_SIZE);
00571     ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
00572 }
00573 
00574 static void write_pts(uint8_t *q, int fourbits, int64_t pts)
00575 {
00576     int val;
00577 
00578     val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
00579     *q++ = val;
00580     val = (((pts >> 15) & 0x7fff) << 1) | 1;
00581     *q++ = val >> 8;
00582     *q++ = val;
00583     val = (((pts) & 0x7fff) << 1) | 1;
00584     *q++ = val >> 8;
00585     *q++ = val;
00586 }
00587 
00588 /* Add a pes header to the front of payload, and segment into an integer number of
00589  * ts packets. The final ts packet is padded using an over-sized adaptation header
00590  * to exactly fill the last ts packet.
00591  * NOTE: 'payload' contains a complete PES payload.
00592  */
00593 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
00594                              const uint8_t *payload, int payload_size,
00595                              int64_t pts, int64_t dts)
00596 {
00597     MpegTSWriteStream *ts_st = st->priv_data;
00598     MpegTSWrite *ts = s->priv_data;
00599     uint8_t buf[TS_PACKET_SIZE];
00600     uint8_t *q;
00601     int val, is_start, len, header_len, write_pcr, private_code, flags;
00602     int afc_len, stuffing_len;
00603     int64_t pcr = -1; /* avoid warning */
00604     int64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
00605 
00606     is_start = 1;
00607     while (payload_size > 0) {
00608         retransmit_si_info(s);
00609 
00610         write_pcr = 0;
00611         if (ts_st->pid == ts_st->service->pcr_pid) {
00612             if (ts->mux_rate > 1 || is_start) // VBR pcr period is based on frames
00613                 ts_st->service->pcr_packet_count++;
00614             if (ts_st->service->pcr_packet_count >=
00615                 ts_st->service->pcr_packet_period) {
00616                 ts_st->service->pcr_packet_count = 0;
00617                 write_pcr = 1;
00618             }
00619         }
00620 
00621         if (ts->mux_rate > 1 && dts != AV_NOPTS_VALUE &&
00622             (dts - (int64_t)ts->cur_pcr) > delay) {
00623             /* pcr insert gets priority over null packet insert */
00624             if (write_pcr)
00625                 mpegts_insert_pcr_only(s, st);
00626             else
00627                 mpegts_insert_null_packet(s);
00628             continue; /* recalculate write_pcr and possibly retransmit si_info */
00629         }
00630 
00631         /* prepare packet header */
00632         q = buf;
00633         *q++ = 0x47;
00634         val = (ts_st->pid >> 8);
00635         if (is_start)
00636             val |= 0x40;
00637         *q++ = val;
00638         *q++ = ts_st->pid;
00639         ts_st->cc = (ts_st->cc + 1) & 0xf;
00640         *q++ = 0x10 | ts_st->cc | (write_pcr ? 0x20 : 0);
00641         if (write_pcr) {
00642             // add 11, pcr references the last byte of program clock reference base
00643             if (ts->mux_rate > 1)
00644                 pcr = ts->cur_pcr + (4+7)*8*90000LL / ts->mux_rate;
00645             else
00646                 pcr = dts - delay;
00647             if (dts != AV_NOPTS_VALUE && dts < pcr)
00648                 av_log(s, AV_LOG_WARNING, "dts < pcr, TS is invalid\n");
00649             *q++ = 7; /* AFC length */
00650             *q++ = 0x10; /* flags: PCR present */
00651             *q++ = pcr >> 25;
00652             *q++ = pcr >> 17;
00653             *q++ = pcr >> 9;
00654             *q++ = pcr >> 1;
00655             *q++ = (pcr & 1) << 7;
00656             *q++ = 0;
00657         }
00658         if (is_start) {
00659             int pes_extension = 0;
00660             /* write PES header */
00661             *q++ = 0x00;
00662             *q++ = 0x00;
00663             *q++ = 0x01;
00664             private_code = 0;
00665             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00666                 if (st->codec->codec_id == CODEC_ID_DIRAC) {
00667                     *q++ = 0xfd;
00668                 } else
00669                     *q++ = 0xe0;
00670             } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO &&
00671                        (st->codec->codec_id == CODEC_ID_MP2 ||
00672                         st->codec->codec_id == CODEC_ID_MP3)) {
00673                 *q++ = 0xc0;
00674             } else {
00675                 *q++ = 0xbd;
00676                 if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
00677                     private_code = 0x20;
00678                 }
00679             }
00680             header_len = 0;
00681             flags = 0;
00682             if (pts != AV_NOPTS_VALUE) {
00683                 header_len += 5;
00684                 flags |= 0x80;
00685             }
00686             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
00687                 header_len += 5;
00688                 flags |= 0x40;
00689             }
00690             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
00691                 st->codec->codec_id == CODEC_ID_DIRAC) {
00692                 /* set PES_extension_flag */
00693                 pes_extension = 1;
00694                 flags |= 0x01;
00695 
00696                 /*
00697                 * One byte for PES2 extension flag +
00698                 * one byte for extension length +
00699                 * one byte for extension id
00700                 */
00701                 header_len += 3;
00702             }
00703             len = payload_size + header_len + 3;
00704             if (private_code != 0)
00705                 len++;
00706             if (len > 0xffff)
00707                 len = 0;
00708             *q++ = len >> 8;
00709             *q++ = len;
00710             val = 0x80;
00711             /* data alignment indicator is required for subtitle data */
00712             if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE)
00713                 val |= 0x04;
00714             *q++ = val;
00715             *q++ = flags;
00716             *q++ = header_len;
00717             if (pts != AV_NOPTS_VALUE) {
00718                 write_pts(q, flags >> 6, pts);
00719                 q += 5;
00720             }
00721             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
00722                 write_pts(q, 1, dts);
00723                 q += 5;
00724             }
00725             if (pes_extension && st->codec->codec_id == CODEC_ID_DIRAC) {
00726                 flags = 0x01;  /* set PES_extension_flag_2 */
00727                 *q++ = flags;
00728                 *q++ = 0x80 | 0x01;  /* marker bit + extension length */
00729                 /*
00730                 * Set the stream id extension flag bit to 0 and
00731                 * write the extended stream id
00732                 */
00733                 *q++ = 0x00 | 0x60;
00734             }
00735             if (private_code != 0)
00736                 *q++ = private_code;
00737             is_start = 0;
00738         }
00739         /* header size */
00740         header_len = q - buf;
00741         /* data len */
00742         len = TS_PACKET_SIZE - header_len;
00743         if (len > payload_size)
00744             len = payload_size;
00745         stuffing_len = TS_PACKET_SIZE - header_len - len;
00746         if (stuffing_len > 0) {
00747             /* add stuffing with AFC */
00748             if (buf[3] & 0x20) {
00749                 /* stuffing already present: increase its size */
00750                 afc_len = buf[4] + 1;
00751                 memmove(buf + 4 + afc_len + stuffing_len,
00752                         buf + 4 + afc_len,
00753                         header_len - (4 + afc_len));
00754                 buf[4] += stuffing_len;
00755                 memset(buf + 4 + afc_len, 0xff, stuffing_len);
00756             } else {
00757                 /* add stuffing */
00758                 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
00759                 buf[3] |= 0x20;
00760                 buf[4] = stuffing_len - 1;
00761                 if (stuffing_len >= 2) {
00762                     buf[5] = 0x00;
00763                     memset(buf + 6, 0xff, stuffing_len - 2);
00764                 }
00765             }
00766         }
00767         memcpy(buf + TS_PACKET_SIZE - len, payload, len);
00768         payload += len;
00769         payload_size -= len;
00770         put_buffer(s->pb, buf, TS_PACKET_SIZE);
00771         ts->cur_pcr += TS_PACKET_SIZE*8*90000LL/ts->mux_rate;
00772     }
00773     put_flush_packet(s->pb);
00774 }
00775 
00776 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
00777 {
00778     AVStream *st = s->streams[pkt->stream_index];
00779     int size = pkt->size;
00780     uint8_t *buf= pkt->data;
00781     uint8_t *data= NULL;
00782     MpegTSWriteStream *ts_st = st->priv_data;
00783     const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE)*2;
00784     int64_t dts = AV_NOPTS_VALUE, pts = AV_NOPTS_VALUE;
00785 
00786     if (pkt->pts != AV_NOPTS_VALUE)
00787         pts = pkt->pts + delay;
00788     if (pkt->dts != AV_NOPTS_VALUE)
00789         dts = pkt->dts + delay;
00790 
00791     if (ts_st->first_pts_check && pts == AV_NOPTS_VALUE) {
00792         av_log(s, AV_LOG_ERROR, "first pts value must set\n");
00793         return -1;
00794     }
00795     ts_st->first_pts_check = 0;
00796 
00797     if (st->codec->codec_id == CODEC_ID_H264) {
00798         const uint8_t *p = buf, *buf_end = p+size;
00799         uint32_t state = -1;
00800 
00801         if (pkt->size < 5 || AV_RB32(pkt->data) != 0x0000001) {
00802             av_log(s, AV_LOG_ERROR, "h264 bitstream malformated, "
00803                    "no startcode found, use -vbsf h264_mp4toannexb\n");
00804             return -1;
00805         }
00806 
00807         do {
00808             p = ff_find_start_code(p, buf_end, &state);
00809             //av_log(s, AV_LOG_INFO, "nal %d\n", state & 0x1f);
00810         } while (p < buf_end && (state & 0x1f) != 9 &&
00811                  (state & 0x1f) != 5 && (state & 0x1f) != 1);
00812 
00813         if ((state & 0x1f) != 9) { // AUD NAL
00814             data = av_malloc(pkt->size+6);
00815             if (!data)
00816                 return -1;
00817             memcpy(data+6, pkt->data, pkt->size);
00818             AV_WB32(data, 0x00000001);
00819             data[4] = 0x09;
00820             data[5] = 0xe0; // any slice type
00821             buf  = data;
00822             size = pkt->size+6;
00823         }
00824     } else if (st->codec->codec_id == CODEC_ID_AAC) {
00825         if (pkt->size < 2)
00826             return -1;
00827         if ((AV_RB16(pkt->data) & 0xfff0) != 0xfff0) {
00828             ADTSContext *adts = ts_st->adts;
00829             int new_size;
00830             if (!adts) {
00831                 av_log(s, AV_LOG_ERROR, "aac bitstream not in adts format "
00832                        "and extradata missing\n");
00833                 return -1;
00834             }
00835             new_size = ADTS_HEADER_SIZE+adts->pce_size+pkt->size;
00836             if ((unsigned)new_size >= INT_MAX)
00837                 return -1;
00838             data = av_malloc(new_size);
00839             if (!data)
00840                 return AVERROR(ENOMEM);
00841             ff_adts_write_frame_header(adts, data, pkt->size, adts->pce_size);
00842             if (adts->pce_size) {
00843                 memcpy(data+ADTS_HEADER_SIZE, adts->pce_data, adts->pce_size);
00844                 adts->pce_size = 0;
00845             }
00846             memcpy(data+ADTS_HEADER_SIZE+adts->pce_size, pkt->data, pkt->size);
00847             buf = data;
00848             size = new_size;
00849         }
00850     }
00851 
00852     if (st->codec->codec_type != AVMEDIA_TYPE_AUDIO) {
00853         // for video and subtitle, write a single pes packet
00854         mpegts_write_pes(s, st, buf, size, pts, dts);
00855         av_free(data);
00856         return 0;
00857     }
00858 
00859     if (ts_st->payload_index + size > DEFAULT_PES_PAYLOAD_SIZE) {
00860         mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
00861                          ts_st->payload_pts, ts_st->payload_dts);
00862         ts_st->payload_index = 0;
00863     }
00864 
00865     if (!ts_st->payload_index) {
00866         ts_st->payload_pts = pts;
00867         ts_st->payload_dts = dts;
00868     }
00869 
00870     memcpy(ts_st->payload + ts_st->payload_index, buf, size);
00871     ts_st->payload_index += size;
00872 
00873     av_free(data);
00874 
00875     return 0;
00876 }
00877 
00878 static int mpegts_write_end(AVFormatContext *s)
00879 {
00880     MpegTSWrite *ts = s->priv_data;
00881     MpegTSWriteStream *ts_st;
00882     MpegTSService *service;
00883     AVStream *st;
00884     int i;
00885 
00886     /* flush current packets */
00887     for(i = 0; i < s->nb_streams; i++) {
00888         st = s->streams[i];
00889         ts_st = st->priv_data;
00890         if (ts_st->payload_index > 0) {
00891             mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_index,
00892                              ts_st->payload_pts, ts_st->payload_dts);
00893         }
00894         av_freep(&ts_st->adts);
00895     }
00896     put_flush_packet(s->pb);
00897 
00898     for(i = 0; i < ts->nb_services; i++) {
00899         service = ts->services[i];
00900         av_freep(&service->provider_name);
00901         av_freep(&service->name);
00902         av_free(service);
00903     }
00904     av_free(ts->services);
00905 
00906     return 0;
00907 }
00908 
00909 AVOutputFormat mpegts_muxer = {
00910     "mpegts",
00911     NULL_IF_CONFIG_SMALL("MPEG-2 transport stream format"),
00912     "video/x-mpegts",
00913     "ts,m2t",
00914     sizeof(MpegTSWrite),
00915     CODEC_ID_MP2,
00916     CODEC_ID_MPEG2VIDEO,
00917     mpegts_write_header,
00918     mpegts_write_packet,
00919     mpegts_write_end,
00920 };