• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • File List
  • Globals

libavformat/mpegtsenc.c

Go to the documentation of this 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 "libavutil/dict.h"
00025 #include "libavutil/mathematics.h"
00026 #include "libavutil/opt.h"
00027 #include "libavutil/avassert.h"
00028 #include "libavcodec/mpegvideo.h"
00029 #include "avformat.h"
00030 #include "internal.h"
00031 #include "mpegts.h"
00032 #include "adts.h"
00033 
00034 #define PCR_TIME_BASE 27000000
00035 
00036 /* write DVB SI sections */
00037 
00038 /*********************************************/
00039 /* mpegts section writer */
00040 
00041 typedef struct MpegTSSection {
00042     int pid;
00043     int cc;
00044     void (*write_packet)(struct MpegTSSection *s, const uint8_t *packet);
00045     void *opaque;
00046 } MpegTSSection;
00047 
00048 typedef struct MpegTSService {
00049     MpegTSSection pmt; /* MPEG2 pmt table context */
00050     int sid;           /* service ID */
00051     char *name;
00052     char *provider_name;
00053     int pcr_pid;
00054     int pcr_packet_count;
00055     int pcr_packet_period;
00056 } MpegTSService;
00057 
00058 typedef struct MpegTSWrite {
00059     const AVClass *av_class;
00060     MpegTSSection pat; /* MPEG2 pat table */
00061     MpegTSSection sdt; /* MPEG2 sdt table context */
00062     MpegTSService **services;
00063     int sdt_packet_count;
00064     int sdt_packet_period;
00065     int pat_packet_count;
00066     int pat_packet_period;
00067     int nb_services;
00068     int onid;
00069     int tsid;
00070     int64_t first_pcr;
00071     int mux_rate; 
00072     int pes_payload_size;
00073 
00074     int transport_stream_id;
00075     int original_network_id;
00076     int service_id;
00077 
00078     int pmt_start_pid;
00079     int start_pid;
00080     int m2ts_mode;
00081 } MpegTSWrite;
00082 
00083 /* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
00084 #define DEFAULT_PES_HEADER_FREQ 16
00085 #define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
00086 
00087 static const AVOption options[] = {
00088     { "mpegts_transport_stream_id", "Set transport_stream_id field.",
00089       offsetof(MpegTSWrite, transport_stream_id), AV_OPT_TYPE_INT, {.dbl = 0x0001 }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
00090     { "mpegts_original_network_id", "Set original_network_id field.",
00091       offsetof(MpegTSWrite, original_network_id), AV_OPT_TYPE_INT, {.dbl = 0x0001 }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
00092     { "mpegts_service_id", "Set service_id field.",
00093       offsetof(MpegTSWrite, service_id), AV_OPT_TYPE_INT, {.dbl = 0x0001 }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
00094     { "mpegts_pmt_start_pid", "Set the first pid of the PMT.",
00095       offsetof(MpegTSWrite, pmt_start_pid), AV_OPT_TYPE_INT, {.dbl = 0x1000 }, 0x0010, 0x1f00, AV_OPT_FLAG_ENCODING_PARAM},
00096     { "mpegts_start_pid", "Set the first pid.",
00097       offsetof(MpegTSWrite, start_pid), AV_OPT_TYPE_INT, {.dbl = 0x0100 }, 0x0100, 0x0f00, AV_OPT_FLAG_ENCODING_PARAM},
00098     {"mpegts_m2ts_mode", "Enable m2ts mode.",
00099         offsetof(MpegTSWrite, m2ts_mode), AV_OPT_TYPE_INT, {.dbl = -1 },
00100         -1,1, AV_OPT_FLAG_ENCODING_PARAM},
00101     { "muxrate", NULL, offsetof(MpegTSWrite, mux_rate), AV_OPT_TYPE_INT, {1}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
00102     { "pes_payload_size", "Minimum PES packet payload in bytes",
00103       offsetof(MpegTSWrite, pes_payload_size), AV_OPT_TYPE_INT, {DEFAULT_PES_PAYLOAD_SIZE}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
00104     { NULL },
00105 };
00106 
00107 static const AVClass mpegts_muxer_class = {
00108     .class_name     = "MPEGTS muxer",
00109     .item_name      = av_default_item_name,
00110     .option         = options,
00111     .version        = LIBAVUTIL_VERSION_INT,
00112 };
00113 
00114 /* NOTE: 4 bytes must be left at the end for the crc32 */
00115 static void mpegts_write_section(MpegTSSection *s, uint8_t *buf, int len)
00116 {
00117     unsigned int crc;
00118     unsigned char packet[TS_PACKET_SIZE];
00119     const unsigned char *buf_ptr;
00120     unsigned char *q;
00121     int first, b, len1, left;
00122 
00123     crc = av_bswap32(av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1, buf, len - 4));
00124     buf[len - 4] = (crc >> 24) & 0xff;
00125     buf[len - 3] = (crc >> 16) & 0xff;
00126     buf[len - 2] = (crc >> 8) & 0xff;
00127     buf[len - 1] = (crc) & 0xff;
00128 
00129     /* send each packet */
00130     buf_ptr = buf;
00131     while (len > 0) {
00132         first = (buf == buf_ptr);
00133         q = packet;
00134         *q++ = 0x47;
00135         b = (s->pid >> 8);
00136         if (first)
00137             b |= 0x40;
00138         *q++ = b;
00139         *q++ = s->pid;
00140         s->cc = (s->cc + 1) & 0xf;
00141         *q++ = 0x10 | s->cc;
00142         if (first)
00143             *q++ = 0; /* 0 offset */
00144         len1 = TS_PACKET_SIZE - (q - packet);
00145         if (len1 > len)
00146             len1 = len;
00147         memcpy(q, buf_ptr, len1);
00148         q += len1;
00149         /* add known padding data */
00150         left = TS_PACKET_SIZE - (q - packet);
00151         if (left > 0)
00152             memset(q, 0xff, left);
00153 
00154         s->write_packet(s, packet);
00155 
00156         buf_ptr += len1;
00157         len -= len1;
00158     }
00159 }
00160 
00161 static inline void put16(uint8_t **q_ptr, int val)
00162 {
00163     uint8_t *q;
00164     q = *q_ptr;
00165     *q++ = val >> 8;
00166     *q++ = val;
00167     *q_ptr = q;
00168 }
00169 
00170 static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
00171                           int version, int sec_num, int last_sec_num,
00172                           uint8_t *buf, int len)
00173 {
00174     uint8_t section[1024], *q;
00175     unsigned int tot_len;
00176     /* reserved_future_use field must be set to 1 for SDT */
00177     unsigned int flags = tid == SDT_TID ? 0xf000 : 0xb000;
00178 
00179     tot_len = 3 + 5 + len + 4;
00180     /* check if not too big */
00181     if (tot_len > 1024)
00182         return AVERROR_INVALIDDATA;
00183 
00184     q = section;
00185     *q++ = tid;
00186     put16(&q, flags | (len + 5 + 4)); /* 5 byte header + 4 byte CRC */
00187     put16(&q, id);
00188     *q++ = 0xc1 | (version << 1); /* current_next_indicator = 1 */
00189     *q++ = sec_num;
00190     *q++ = last_sec_num;
00191     memcpy(q, buf, len);
00192 
00193     mpegts_write_section(s, section, tot_len);
00194     return 0;
00195 }
00196 
00197 /*********************************************/
00198 /* mpegts writer */
00199 
00200 #define DEFAULT_PROVIDER_NAME   "FFmpeg"
00201 #define DEFAULT_SERVICE_NAME    "Service01"
00202 
00203 /* we retransmit the SI info at this rate */
00204 #define SDT_RETRANS_TIME 500
00205 #define PAT_RETRANS_TIME 100
00206 #define PCR_RETRANS_TIME 20
00207 
00208 typedef struct MpegTSWriteStream {
00209     struct MpegTSService *service;
00210     int pid; /* stream associated pid */
00211     int cc;
00212     int payload_size;
00213     int first_pts_check; 
00214     int64_t payload_pts;
00215     int64_t payload_dts;
00216     int payload_flags;
00217     uint8_t *payload;
00218     ADTSContext *adts;
00219 } MpegTSWriteStream;
00220 
00221 static void mpegts_write_pat(AVFormatContext *s)
00222 {
00223     MpegTSWrite *ts = s->priv_data;
00224     MpegTSService *service;
00225     uint8_t data[1012], *q;
00226     int i;
00227 
00228     q = data;
00229     for(i = 0; i < ts->nb_services; i++) {
00230         service = ts->services[i];
00231         put16(&q, service->sid);
00232         put16(&q, 0xe000 | service->pmt.pid);
00233     }
00234     mpegts_write_section1(&ts->pat, PAT_TID, ts->tsid, 0, 0, 0,
00235                           data, q - data);
00236 }
00237 
00238 static void mpegts_write_pmt(AVFormatContext *s, MpegTSService *service)
00239 {
00240     //    MpegTSWrite *ts = s->priv_data;
00241     uint8_t data[1012], *q, *desc_length_ptr, *program_info_length_ptr;
00242     int val, stream_type, i;
00243 
00244     q = data;
00245     put16(&q, 0xe000 | service->pcr_pid);
00246 
00247     program_info_length_ptr = q;
00248     q += 2; /* patched after */
00249 
00250     /* put program info here */
00251 
00252     val = 0xf000 | (q - program_info_length_ptr - 2);
00253     program_info_length_ptr[0] = val >> 8;
00254     program_info_length_ptr[1] = val;
00255 
00256     for(i = 0; i < s->nb_streams; i++) {
00257         AVStream *st = s->streams[i];
00258         MpegTSWriteStream *ts_st = st->priv_data;
00259         AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL,0);
00260         switch(st->codec->codec_id) {
00261         case CODEC_ID_MPEG1VIDEO:
00262         case CODEC_ID_MPEG2VIDEO:
00263             stream_type = STREAM_TYPE_VIDEO_MPEG2;
00264             break;
00265         case CODEC_ID_MPEG4:
00266             stream_type = STREAM_TYPE_VIDEO_MPEG4;
00267             break;
00268         case CODEC_ID_H264:
00269             stream_type = STREAM_TYPE_VIDEO_H264;
00270             break;
00271         case CODEC_ID_DIRAC:
00272             stream_type = STREAM_TYPE_VIDEO_DIRAC;
00273             break;
00274         case CODEC_ID_MP2:
00275         case CODEC_ID_MP3:
00276             stream_type = STREAM_TYPE_AUDIO_MPEG1;
00277             break;
00278         case CODEC_ID_AAC:
00279             stream_type = STREAM_TYPE_AUDIO_AAC;
00280             break;
00281         case CODEC_ID_AAC_LATM:
00282             stream_type = STREAM_TYPE_AUDIO_AAC_LATM;
00283             break;
00284         case CODEC_ID_AC3:
00285             stream_type = STREAM_TYPE_AUDIO_AC3;
00286             break;
00287         default:
00288             stream_type = STREAM_TYPE_PRIVATE_DATA;
00289             break;
00290         }
00291         *q++ = stream_type;
00292         put16(&q, 0xe000 | ts_st->pid);
00293         desc_length_ptr = q;
00294         q += 2; /* patched after */
00295 
00296         /* write optional descriptors here */
00297         switch(st->codec->codec_type) {
00298         case AVMEDIA_TYPE_AUDIO:
00299             if(st->codec->codec_id==CODEC_ID_EAC3){
00300                 *q++=0x7a; // EAC3 descriptor see A038 DVB SI
00301                 *q++=1; // 1 byte, all flags sets to 0
00302                 *q++=0; // omit all fields...
00303             }
00304 
00305             if (lang) {
00306                 char *p;
00307                 char *next = lang->value;
00308                 uint8_t *len_ptr;
00309 
00310                 *q++ = 0x0a; /* ISO 639 language descriptor */
00311                 len_ptr = q++;
00312                 *len_ptr = 0;
00313 
00314                 for (p = lang->value; next && *len_ptr < 255 / 4 * 4; p = next + 1) {
00315                     next = strchr(p, ',');
00316                     if (strlen(p) != 3 && (!next || next != p + 3))
00317                         continue; /* not a 3-letter code */
00318 
00319                     *q++ = *p++;
00320                     *q++ = *p++;
00321                     *q++ = *p++;
00322 
00323                 if (st->disposition & AV_DISPOSITION_CLEAN_EFFECTS)
00324                     *q++ = 0x01;
00325                 else if (st->disposition & AV_DISPOSITION_HEARING_IMPAIRED)
00326                     *q++ = 0x02;
00327                 else if (st->disposition & AV_DISPOSITION_VISUAL_IMPAIRED)
00328                     *q++ = 0x03;
00329                 else
00330                     *q++ = 0; /* undefined type */
00331 
00332                     *len_ptr += 4;
00333                 }
00334 
00335                 if (*len_ptr == 0)
00336                     q -= 2; /* no language codes were written */
00337             }
00338             break;
00339         case AVMEDIA_TYPE_SUBTITLE:
00340             {
00341                 const char *language;
00342                 language = lang && strlen(lang->value)==3 ? lang->value : "eng";
00343                 *q++ = 0x59;
00344                 *q++ = 8;
00345                 *q++ = language[0];
00346                 *q++ = language[1];
00347                 *q++ = language[2];
00348                 *q++ = 0x10; /* normal subtitles (0x20 = if hearing pb) */
00349                 if(st->codec->extradata_size == 4) {
00350                     memcpy(q, st->codec->extradata, 4);
00351                     q += 4;
00352                 } else {
00353                     put16(&q, 1); /* page id */
00354                     put16(&q, 1); /* ancillary page id */
00355                 }
00356             }
00357             break;
00358         case AVMEDIA_TYPE_VIDEO:
00359             if (stream_type == STREAM_TYPE_VIDEO_DIRAC) {
00360                 *q++ = 0x05; /*MPEG-2 registration descriptor*/
00361                 *q++ = 4;
00362                 *q++ = 'd';
00363                 *q++ = 'r';
00364                 *q++ = 'a';
00365                 *q++ = 'c';
00366             }
00367             break;
00368         }
00369 
00370         val = 0xf000 | (q - desc_length_ptr - 2);
00371         desc_length_ptr[0] = val >> 8;
00372         desc_length_ptr[1] = val;
00373     }
00374     mpegts_write_section1(&service->pmt, PMT_TID, service->sid, 0, 0, 0,
00375                           data, q - data);
00376 }
00377 
00378 /* NOTE: str == NULL is accepted for an empty string */
00379 static void putstr8(uint8_t **q_ptr, const char *str)
00380 {
00381     uint8_t *q;
00382     int len;
00383 
00384     q = *q_ptr;
00385     if (!str)
00386         len = 0;
00387     else
00388         len = strlen(str);
00389     *q++ = len;
00390     memcpy(q, str, len);
00391     q += len;
00392     *q_ptr = q;
00393 }
00394 
00395 static void mpegts_write_sdt(AVFormatContext *s)
00396 {
00397     MpegTSWrite *ts = s->priv_data;
00398     MpegTSService *service;
00399     uint8_t data[1012], *q, *desc_list_len_ptr, *desc_len_ptr;
00400     int i, running_status, free_ca_mode, val;
00401 
00402     q = data;
00403     put16(&q, ts->onid);
00404     *q++ = 0xff;
00405     for(i = 0; i < ts->nb_services; i++) {
00406         service = ts->services[i];
00407         put16(&q, service->sid);
00408         *q++ = 0xfc | 0x00; /* currently no EIT info */
00409         desc_list_len_ptr = q;
00410         q += 2;
00411         running_status = 4; /* running */
00412         free_ca_mode = 0;
00413 
00414         /* write only one descriptor for the service name and provider */
00415         *q++ = 0x48;
00416         desc_len_ptr = q;
00417         q++;
00418         *q++ = 0x01; /* digital television service */
00419         putstr8(&q, service->provider_name);
00420         putstr8(&q, service->name);
00421         desc_len_ptr[0] = q - desc_len_ptr - 1;
00422 
00423         /* fill descriptor length */
00424         val = (running_status << 13) | (free_ca_mode << 12) |
00425             (q - desc_list_len_ptr - 2);
00426         desc_list_len_ptr[0] = val >> 8;
00427         desc_list_len_ptr[1] = val;
00428     }
00429     mpegts_write_section1(&ts->sdt, SDT_TID, ts->tsid, 0, 0, 0,
00430                           data, q - data);
00431 }
00432 
00433 static MpegTSService *mpegts_add_service(MpegTSWrite *ts,
00434                                          int sid,
00435                                          const char *provider_name,
00436                                          const char *name)
00437 {
00438     MpegTSService *service;
00439 
00440     service = av_mallocz(sizeof(MpegTSService));
00441     if (!service)
00442         return NULL;
00443     service->pmt.pid = ts->pmt_start_pid + ts->nb_services;
00444     service->sid = sid;
00445     service->provider_name = av_strdup(provider_name);
00446     service->name = av_strdup(name);
00447     service->pcr_pid = 0x1fff;
00448     dynarray_add(&ts->services, &ts->nb_services, service);
00449     return service;
00450 }
00451 
00452 static int64_t get_pcr(const MpegTSWrite *ts, AVIOContext *pb)
00453 {
00454     return av_rescale(avio_tell(pb) + 11, 8 * PCR_TIME_BASE, ts->mux_rate) +
00455            ts->first_pcr;
00456 }
00457 
00458 static void mpegts_prefix_m2ts_header(AVFormatContext *s)
00459 {
00460     MpegTSWrite *ts = s->priv_data;
00461     if (ts->m2ts_mode) {
00462         int64_t pcr = get_pcr(s->priv_data, s->pb);
00463         uint32_t tp_extra_header = pcr % 0x3fffffff;
00464         tp_extra_header = AV_RB32(&tp_extra_header);
00465         avio_write(s->pb, (unsigned char *) &tp_extra_header,
00466                 sizeof(tp_extra_header));
00467     }
00468 }
00469 
00470 static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
00471 {
00472     AVFormatContext *ctx = s->opaque;
00473     mpegts_prefix_m2ts_header(ctx);
00474     avio_write(ctx->pb, packet, TS_PACKET_SIZE);
00475 }
00476 
00477 static int mpegts_write_header(AVFormatContext *s)
00478 {
00479     MpegTSWrite *ts = s->priv_data;
00480     MpegTSWriteStream *ts_st;
00481     MpegTSService *service;
00482     AVStream *st, *pcr_st = NULL;
00483     AVDictionaryEntry *title, *provider;
00484     int i, j;
00485     const char *service_name;
00486     const char *provider_name;
00487     int *pids;
00488 
00489     // round up to a whole number of TS packets
00490     ts->pes_payload_size = (ts->pes_payload_size + 14 + 183) / 184 * 184 - 14;
00491 
00492     ts->tsid = ts->transport_stream_id;
00493     ts->onid = ts->original_network_id;
00494     /* allocate a single DVB service */
00495     title = av_dict_get(s->metadata, "service_name", NULL, 0);
00496     if (!title)
00497         title = av_dict_get(s->metadata, "title", NULL, 0);
00498     service_name = title ? title->value : DEFAULT_SERVICE_NAME;
00499     provider = av_dict_get(s->metadata, "service_provider", NULL, 0);
00500     provider_name = provider ? provider->value : DEFAULT_PROVIDER_NAME;
00501     service = mpegts_add_service(ts, ts->service_id, provider_name, service_name);
00502     service->pmt.write_packet = section_write_packet;
00503     service->pmt.opaque = s;
00504     service->pmt.cc = 15;
00505 
00506     ts->pat.pid = PAT_PID;
00507     ts->pat.cc = 15; // Initialize at 15 so that it wraps and be equal to 0 for the first packet we write
00508     ts->pat.write_packet = section_write_packet;
00509     ts->pat.opaque = s;
00510 
00511     ts->sdt.pid = SDT_PID;
00512     ts->sdt.cc = 15;
00513     ts->sdt.write_packet = section_write_packet;
00514     ts->sdt.opaque = s;
00515 
00516     pids = av_malloc(s->nb_streams * sizeof(*pids));
00517     if (!pids)
00518         return AVERROR(ENOMEM);
00519 
00520     /* assign pids to each stream */
00521     for(i = 0;i < s->nb_streams; i++) {
00522         st = s->streams[i];
00523         avpriv_set_pts_info(st, 33, 1, 90000);
00524         ts_st = av_mallocz(sizeof(MpegTSWriteStream));
00525         if (!ts_st)
00526             goto fail;
00527         st->priv_data = ts_st;
00528         ts_st->payload = av_mallocz(ts->pes_payload_size);
00529         if (!ts_st->payload)
00530             goto fail;
00531         ts_st->service = service;
00532         /* MPEG pid values < 16 are reserved. Applications which set st->id in
00533          * this range are assigned a calculated pid. */
00534         if (st->id < 16) {
00535             ts_st->pid = ts->start_pid + i;
00536         } else if (st->id < 0x1FFF) {
00537             ts_st->pid = st->id;
00538         } else {
00539             av_log(s, AV_LOG_ERROR, "Invalid stream id %d, must be less than 8191\n", st->id);
00540             goto fail;
00541         }
00542         if (ts_st->pid == service->pmt.pid) {
00543             av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
00544             goto fail;
00545         }
00546         for (j = 0; j < i; j++)
00547             if (pids[j] == ts_st->pid) {
00548                 av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
00549                 goto fail;
00550             }
00551         pids[i] = ts_st->pid;
00552         ts_st->payload_pts = AV_NOPTS_VALUE;
00553         ts_st->payload_dts = AV_NOPTS_VALUE;
00554         ts_st->first_pts_check = 1;
00555         ts_st->cc = 15;
00556         /* update PCR pid by using the first video stream */
00557         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
00558             service->pcr_pid == 0x1fff) {
00559             service->pcr_pid = ts_st->pid;
00560             pcr_st = st;
00561         }
00562         if (st->codec->codec_id == CODEC_ID_AAC &&
00563             st->codec->extradata_size > 0) {
00564             ts_st->adts = av_mallocz(sizeof(*ts_st->adts));
00565             if (!ts_st->adts)
00566                 goto fail;
00567             if (ff_adts_decode_extradata(s, ts_st->adts, st->codec->extradata,
00568                                          st->codec->extradata_size) < 0)
00569                 goto fail;
00570         }
00571     }
00572 
00573     av_free(pids);
00574 
00575     /* if no video stream, use the first stream as PCR */
00576     if (service->pcr_pid == 0x1fff && s->nb_streams > 0) {
00577         pcr_st = s->streams[0];
00578         ts_st = pcr_st->priv_data;
00579         service->pcr_pid = ts_st->pid;
00580     }
00581 
00582 #if FF_API_MUXRATE
00583     if (s->mux_rate)
00584         ts->mux_rate = s->mux_rate;
00585 #endif
00586 
00587     if (ts->mux_rate > 1) {
00588         service->pcr_packet_period = (ts->mux_rate * PCR_RETRANS_TIME) /
00589             (TS_PACKET_SIZE * 8 * 1000);
00590         ts->sdt_packet_period      = (ts->mux_rate * SDT_RETRANS_TIME) /
00591             (TS_PACKET_SIZE * 8 * 1000);
00592         ts->pat_packet_period      = (ts->mux_rate * PAT_RETRANS_TIME) /
00593             (TS_PACKET_SIZE * 8 * 1000);
00594 
00595         ts->first_pcr = av_rescale(s->max_delay, PCR_TIME_BASE, AV_TIME_BASE);
00596     } else {
00597         /* Arbitrary values, PAT/PMT could be written on key frames */
00598         ts->sdt_packet_period = 200;
00599         ts->pat_packet_period = 40;
00600         if (pcr_st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
00601             if (!pcr_st->codec->frame_size) {
00602                 av_log(s, AV_LOG_WARNING, "frame size not set\n");
00603                 service->pcr_packet_period =
00604                     pcr_st->codec->sample_rate/(10*512);
00605             } else {
00606                 service->pcr_packet_period =
00607                     pcr_st->codec->sample_rate/(10*pcr_st->codec->frame_size);
00608             }
00609         } else {
00610             // max delta PCR 0.1s
00611             service->pcr_packet_period =
00612                 pcr_st->codec->time_base.den/(10*pcr_st->codec->time_base.num);
00613         }
00614     }
00615 
00616     // output a PCR as soon as possible
00617     service->pcr_packet_count = service->pcr_packet_period;
00618     ts->pat_packet_count = ts->pat_packet_period-1;
00619     ts->sdt_packet_count = ts->sdt_packet_period-1;
00620 
00621     if (ts->mux_rate == 1)
00622         av_log(s, AV_LOG_INFO, "muxrate VBR, ");
00623     else
00624         av_log(s, AV_LOG_INFO, "muxrate %d, ", ts->mux_rate);
00625     av_log(s, AV_LOG_INFO, "pcr every %d pkts, "
00626            "sdt every %d, pat/pmt every %d pkts\n",
00627            service->pcr_packet_period,
00628            ts->sdt_packet_period, ts->pat_packet_period);
00629 
00630     if (ts->m2ts_mode == -1) {
00631         if (av_match_ext(s->filename, "m2ts")) {
00632             ts->m2ts_mode = 1;
00633         } else {
00634             ts->m2ts_mode = 0;
00635         }
00636     }
00637 
00638     avio_flush(s->pb);
00639 
00640     return 0;
00641 
00642  fail:
00643     av_free(pids);
00644     for(i = 0;i < s->nb_streams; i++) {
00645         MpegTSWriteStream *ts_st;
00646         st = s->streams[i];
00647         ts_st = st->priv_data;
00648         if (ts_st) {
00649             av_freep(&ts_st->payload);
00650             av_freep(&ts_st->adts);
00651         }
00652         av_freep(&st->priv_data);
00653     }
00654     return AVERROR(EINVAL);
00655 }
00656 
00657 /* send SDT, PAT and PMT tables regulary */
00658 static void retransmit_si_info(AVFormatContext *s)
00659 {
00660     MpegTSWrite *ts = s->priv_data;
00661     int i;
00662 
00663     if (++ts->sdt_packet_count == ts->sdt_packet_period) {
00664         ts->sdt_packet_count = 0;
00665         mpegts_write_sdt(s);
00666     }
00667     if (++ts->pat_packet_count == ts->pat_packet_period) {
00668         ts->pat_packet_count = 0;
00669         mpegts_write_pat(s);
00670         for(i = 0; i < ts->nb_services; i++) {
00671             mpegts_write_pmt(s, ts->services[i]);
00672         }
00673     }
00674 }
00675 
00676 static int write_pcr_bits(uint8_t *buf, int64_t pcr)
00677 {
00678     int64_t pcr_low = pcr % 300, pcr_high = pcr / 300;
00679 
00680     *buf++ = pcr_high >> 25;
00681     *buf++ = pcr_high >> 17;
00682     *buf++ = pcr_high >> 9;
00683     *buf++ = pcr_high >> 1;
00684     *buf++ = pcr_high << 7 | pcr_low >> 8 | 0x7e;
00685     *buf++ = pcr_low;
00686 
00687     return 6;
00688 }
00689 
00690 /* Write a single null transport stream packet */
00691 static void mpegts_insert_null_packet(AVFormatContext *s)
00692 {
00693     uint8_t *q;
00694     uint8_t buf[TS_PACKET_SIZE];
00695 
00696     q = buf;
00697     *q++ = 0x47;
00698     *q++ = 0x00 | 0x1f;
00699     *q++ = 0xff;
00700     *q++ = 0x10;
00701     memset(q, 0x0FF, TS_PACKET_SIZE - (q - buf));
00702     mpegts_prefix_m2ts_header(s);
00703     avio_write(s->pb, buf, TS_PACKET_SIZE);
00704 }
00705 
00706 /* Write a single transport stream packet with a PCR and no payload */
00707 static void mpegts_insert_pcr_only(AVFormatContext *s, AVStream *st)
00708 {
00709     MpegTSWrite *ts = s->priv_data;
00710     MpegTSWriteStream *ts_st = st->priv_data;
00711     uint8_t *q;
00712     uint8_t buf[TS_PACKET_SIZE];
00713 
00714     q = buf;
00715     *q++ = 0x47;
00716     *q++ = ts_st->pid >> 8;
00717     *q++ = ts_st->pid;
00718     *q++ = 0x20 | ts_st->cc;   /* Adaptation only */
00719     /* Continuity Count field does not increment (see 13818-1 section 2.4.3.3) */
00720     *q++ = TS_PACKET_SIZE - 5; /* Adaptation Field Length */
00721     *q++ = 0x10;               /* Adaptation flags: PCR present */
00722 
00723     /* PCR coded into 6 bytes */
00724     q += write_pcr_bits(q, get_pcr(ts, s->pb));
00725 
00726     /* stuffing bytes */
00727     memset(q, 0xFF, TS_PACKET_SIZE - (q - buf));
00728     mpegts_prefix_m2ts_header(s);
00729     avio_write(s->pb, buf, TS_PACKET_SIZE);
00730 }
00731 
00732 static void write_pts(uint8_t *q, int fourbits, int64_t pts)
00733 {
00734     int val;
00735 
00736     val = fourbits << 4 | (((pts >> 30) & 0x07) << 1) | 1;
00737     *q++ = val;
00738     val = (((pts >> 15) & 0x7fff) << 1) | 1;
00739     *q++ = val >> 8;
00740     *q++ = val;
00741     val = (((pts) & 0x7fff) << 1) | 1;
00742     *q++ = val >> 8;
00743     *q++ = val;
00744 }
00745 
00746 /* Set an adaptation field flag in an MPEG-TS packet*/
00747 static void set_af_flag(uint8_t *pkt, int flag)
00748 {
00749     // expect at least one flag to set
00750     assert(flag);
00751 
00752     if ((pkt[3] & 0x20) == 0) {
00753         // no AF yet, set adaptation field flag
00754         pkt[3] |= 0x20;
00755         // 1 byte length, no flags
00756         pkt[4] = 1;
00757         pkt[5] = 0;
00758     }
00759     pkt[5] |= flag;
00760 }
00761 
00762 /* Extend the adaptation field by size bytes */
00763 static void extend_af(uint8_t *pkt, int size)
00764 {
00765     // expect already existing adaptation field
00766     assert(pkt[3] & 0x20);
00767     pkt[4] += size;
00768 }
00769 
00770 /* Get a pointer to MPEG-TS payload (right after TS packet header) */
00771 static uint8_t *get_ts_payload_start(uint8_t *pkt)
00772 {
00773     if (pkt[3] & 0x20)
00774         return pkt + 5 + pkt[4];
00775     else
00776         return pkt + 4;
00777 }
00778 
00779 /* Add a pes header to the front of payload, and segment into an integer number of
00780  * ts packets. The final ts packet is padded using an over-sized adaptation header
00781  * to exactly fill the last ts packet.
00782  * NOTE: 'payload' contains a complete PES payload.
00783  */
00784 static void mpegts_write_pes(AVFormatContext *s, AVStream *st,
00785                              const uint8_t *payload, int payload_size,
00786                              int64_t pts, int64_t dts, int key)
00787 {
00788     MpegTSWriteStream *ts_st = st->priv_data;
00789     MpegTSWrite *ts = s->priv_data;
00790     uint8_t buf[TS_PACKET_SIZE];
00791     uint8_t *q;
00792     int val, is_start, len, header_len, write_pcr, private_code, flags;
00793     int afc_len, stuffing_len;
00794     int64_t pcr = -1; /* avoid warning */
00795     int64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE);
00796 
00797     is_start = 1;
00798     while (payload_size > 0) {
00799         retransmit_si_info(s);
00800 
00801         write_pcr = 0;
00802         if (ts_st->pid == ts_st->service->pcr_pid) {
00803             if (ts->mux_rate > 1 || is_start) // VBR pcr period is based on frames
00804                 ts_st->service->pcr_packet_count++;
00805             if (ts_st->service->pcr_packet_count >=
00806                 ts_st->service->pcr_packet_period) {
00807                 ts_st->service->pcr_packet_count = 0;
00808                 write_pcr = 1;
00809             }
00810         }
00811 
00812         if (ts->mux_rate > 1 && dts != AV_NOPTS_VALUE &&
00813             (dts - get_pcr(ts, s->pb)/300) > delay) {
00814             /* pcr insert gets priority over null packet insert */
00815             if (write_pcr)
00816                 mpegts_insert_pcr_only(s, st);
00817             else
00818                 mpegts_insert_null_packet(s);
00819             continue; /* recalculate write_pcr and possibly retransmit si_info */
00820         }
00821 
00822         /* prepare packet header */
00823         q = buf;
00824         *q++ = 0x47;
00825         val = (ts_st->pid >> 8);
00826         if (is_start)
00827             val |= 0x40;
00828         *q++ = val;
00829         *q++ = ts_st->pid;
00830         ts_st->cc = (ts_st->cc + 1) & 0xf;
00831         *q++ = 0x10 | ts_st->cc; // payload indicator + CC
00832         if (key && is_start && pts != AV_NOPTS_VALUE) {
00833             // set Random Access for key frames
00834             if (ts_st->pid == ts_st->service->pcr_pid)
00835                 write_pcr = 1;
00836             set_af_flag(buf, 0x40);
00837             q = get_ts_payload_start(buf);
00838         }
00839         if (write_pcr) {
00840             set_af_flag(buf, 0x10);
00841             q = get_ts_payload_start(buf);
00842             // add 11, pcr references the last byte of program clock reference base
00843             if (ts->mux_rate > 1)
00844                 pcr = get_pcr(ts, s->pb);
00845             else
00846                 pcr = (dts - delay)*300;
00847             if (dts != AV_NOPTS_VALUE && dts < pcr / 300)
00848                 av_log(s, AV_LOG_WARNING, "dts < pcr, TS is invalid\n");
00849             extend_af(buf, write_pcr_bits(q, pcr));
00850             q = get_ts_payload_start(buf);
00851         }
00852         if (is_start) {
00853             int pes_extension = 0;
00854             /* write PES header */
00855             *q++ = 0x00;
00856             *q++ = 0x00;
00857             *q++ = 0x01;
00858             private_code = 0;
00859             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00860                 if (st->codec->codec_id == CODEC_ID_DIRAC) {
00861                     *q++ = 0xfd;
00862                 } else
00863                     *q++ = 0xe0;
00864             } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO &&
00865                        (st->codec->codec_id == CODEC_ID_MP2 ||
00866                         st->codec->codec_id == CODEC_ID_MP3 ||
00867                         st->codec->codec_id == CODEC_ID_AAC)) {
00868                 *q++ = 0xc0;
00869             } else {
00870                 *q++ = 0xbd;
00871                 if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
00872                     private_code = 0x20;
00873                 }
00874             }
00875             header_len = 0;
00876             flags = 0;
00877             if (pts != AV_NOPTS_VALUE) {
00878                 header_len += 5;
00879                 flags |= 0x80;
00880             }
00881             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
00882                 header_len += 5;
00883                 flags |= 0x40;
00884             }
00885             if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
00886                 st->codec->codec_id == CODEC_ID_DIRAC) {
00887                 /* set PES_extension_flag */
00888                 pes_extension = 1;
00889                 flags |= 0x01;
00890 
00891                 /*
00892                 * One byte for PES2 extension flag +
00893                 * one byte for extension length +
00894                 * one byte for extension id
00895                 */
00896                 header_len += 3;
00897             }
00898             len = payload_size + header_len + 3;
00899             if (private_code != 0)
00900                 len++;
00901             if (len > 0xffff)
00902                 len = 0;
00903             *q++ = len >> 8;
00904             *q++ = len;
00905             val = 0x80;
00906             /* data alignment indicator is required for subtitle data */
00907             if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE)
00908                 val |= 0x04;
00909             *q++ = val;
00910             *q++ = flags;
00911             *q++ = header_len;
00912             if (pts != AV_NOPTS_VALUE) {
00913                 write_pts(q, flags >> 6, pts);
00914                 q += 5;
00915             }
00916             if (dts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && dts != pts) {
00917                 write_pts(q, 1, dts);
00918                 q += 5;
00919             }
00920             if (pes_extension && st->codec->codec_id == CODEC_ID_DIRAC) {
00921                 flags = 0x01;  /* set PES_extension_flag_2 */
00922                 *q++ = flags;
00923                 *q++ = 0x80 | 0x01;  /* marker bit + extension length */
00924                 /*
00925                 * Set the stream id extension flag bit to 0 and
00926                 * write the extended stream id
00927                 */
00928                 *q++ = 0x00 | 0x60;
00929             }
00930             if (private_code != 0)
00931                 *q++ = private_code;
00932             is_start = 0;
00933         }
00934         /* header size */
00935         header_len = q - buf;
00936         /* data len */
00937         len = TS_PACKET_SIZE - header_len;
00938         if (len > payload_size)
00939             len = payload_size;
00940         stuffing_len = TS_PACKET_SIZE - header_len - len;
00941         if (stuffing_len > 0) {
00942             /* add stuffing with AFC */
00943             if (buf[3] & 0x20) {
00944                 /* stuffing already present: increase its size */
00945                 afc_len = buf[4] + 1;
00946                 memmove(buf + 4 + afc_len + stuffing_len,
00947                         buf + 4 + afc_len,
00948                         header_len - (4 + afc_len));
00949                 buf[4] += stuffing_len;
00950                 memset(buf + 4 + afc_len, 0xff, stuffing_len);
00951             } else {
00952                 /* add stuffing */
00953                 memmove(buf + 4 + stuffing_len, buf + 4, header_len - 4);
00954                 buf[3] |= 0x20;
00955                 buf[4] = stuffing_len - 1;
00956                 if (stuffing_len >= 2) {
00957                     buf[5] = 0x00;
00958                     memset(buf + 6, 0xff, stuffing_len - 2);
00959                 }
00960             }
00961         }
00962         memcpy(buf + TS_PACKET_SIZE - len, payload, len);
00963         payload += len;
00964         payload_size -= len;
00965         mpegts_prefix_m2ts_header(s);
00966         avio_write(s->pb, buf, TS_PACKET_SIZE);
00967     }
00968     avio_flush(s->pb);
00969 }
00970 
00971 static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
00972 {
00973     AVStream *st = s->streams[pkt->stream_index];
00974     int size = pkt->size;
00975     uint8_t *buf= pkt->data;
00976     uint8_t *data= NULL;
00977     MpegTSWrite *ts = s->priv_data;
00978     MpegTSWriteStream *ts_st = st->priv_data;
00979     const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE)*2;
00980     int64_t dts = AV_NOPTS_VALUE, pts = AV_NOPTS_VALUE;
00981 
00982     if (pkt->pts != AV_NOPTS_VALUE)
00983         pts = pkt->pts + delay;
00984     if (pkt->dts != AV_NOPTS_VALUE)
00985         dts = pkt->dts + delay;
00986 
00987     if (ts_st->first_pts_check && pts == AV_NOPTS_VALUE) {
00988         av_log(s, AV_LOG_ERROR, "first pts value must set\n");
00989         return AVERROR_INVALIDDATA;
00990     }
00991     ts_st->first_pts_check = 0;
00992 
00993     if (st->codec->codec_id == CODEC_ID_H264) {
00994         const uint8_t *p = buf, *buf_end = p+size;
00995         uint32_t state = -1;
00996 
00997         if (pkt->size < 5 || AV_RB32(pkt->data) != 0x0000001) {
00998             av_log(s, AV_LOG_ERROR, "H.264 bitstream malformed, "
00999                    "no startcode found, use the h264_mp4toannexb bitstream filter\n");
01000             return AVERROR_INVALIDDATA;
01001         }
01002 
01003         do {
01004             p = avpriv_mpv_find_start_code(p, buf_end, &state);
01005             //av_log(s, AV_LOG_INFO, "nal %d\n", state & 0x1f);
01006         } while (p < buf_end && (state & 0x1f) != 9 &&
01007                  (state & 0x1f) != 5 && (state & 0x1f) != 1);
01008 
01009         if ((state & 0x1f) != 9) { // AUD NAL
01010             data = av_malloc(pkt->size+6);
01011             if (!data)
01012                 return AVERROR(ENOMEM);
01013             memcpy(data+6, pkt->data, pkt->size);
01014             AV_WB32(data, 0x00000001);
01015             data[4] = 0x09;
01016             data[5] = 0xf0; // any slice type (0xe) + rbsp stop one bit
01017             buf  = data;
01018             size = pkt->size+6;
01019         }
01020     } else if (st->codec->codec_id == CODEC_ID_AAC) {
01021         if (pkt->size < 2)
01022             return AVERROR_INVALIDDATA;
01023         if ((AV_RB16(pkt->data) & 0xfff0) != 0xfff0) {
01024             ADTSContext *adts = ts_st->adts;
01025             int new_size, err;
01026             if (!adts) {
01027                 av_log(s, AV_LOG_ERROR, "AAC bitstream not in ADTS format "
01028                        "and extradata missing\n");
01029                 return AVERROR_INVALIDDATA;
01030             }
01031             new_size = ADTS_HEADER_SIZE+adts->pce_size+pkt->size;
01032             if ((unsigned)new_size >= INT_MAX)
01033                 return AVERROR_INVALIDDATA;
01034             data = av_malloc(new_size);
01035             if (!data)
01036                 return AVERROR(ENOMEM);
01037             err = ff_adts_write_frame_header(adts, data, pkt->size,
01038                                              adts->pce_size);
01039             if (err < 0) {
01040                 av_free(data);
01041                 return err;
01042             }
01043             if (adts->pce_size) {
01044                 memcpy(data+ADTS_HEADER_SIZE, adts->pce_data, adts->pce_size);
01045                 adts->pce_size = 0;
01046             }
01047             memcpy(data+ADTS_HEADER_SIZE+adts->pce_size, pkt->data, pkt->size);
01048             buf = data;
01049             size = new_size;
01050         }
01051     }
01052 
01053     if (ts_st->payload_size && ts_st->payload_size + size > ts->pes_payload_size) {
01054         mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_size,
01055                          ts_st->payload_pts, ts_st->payload_dts,
01056                          ts_st->payload_flags & AV_PKT_FLAG_KEY);
01057         ts_st->payload_size = 0;
01058     }
01059 
01060     if (st->codec->codec_type != AVMEDIA_TYPE_AUDIO || size > ts->pes_payload_size) {
01061         av_assert0(!ts_st->payload_size);
01062         // for video and subtitle, write a single pes packet
01063         mpegts_write_pes(s, st, buf, size, pts, dts, pkt->flags & AV_PKT_FLAG_KEY);
01064         av_free(data);
01065         return 0;
01066     }
01067 
01068     if (!ts_st->payload_size) {
01069         ts_st->payload_pts = pts;
01070         ts_st->payload_dts = dts;
01071         ts_st->payload_flags = pkt->flags;
01072     }
01073 
01074     memcpy(ts_st->payload + ts_st->payload_size, buf, size);
01075     ts_st->payload_size += size;
01076 
01077     av_free(data);
01078 
01079     return 0;
01080 }
01081 
01082 static int mpegts_write_end(AVFormatContext *s)
01083 {
01084     MpegTSWrite *ts = s->priv_data;
01085     MpegTSWriteStream *ts_st;
01086     MpegTSService *service;
01087     AVStream *st;
01088     int i;
01089 
01090     /* flush current packets */
01091     for(i = 0; i < s->nb_streams; i++) {
01092         st = s->streams[i];
01093         ts_st = st->priv_data;
01094         if (ts_st->payload_size > 0) {
01095             mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_size,
01096                              ts_st->payload_pts, ts_st->payload_dts,
01097                              ts_st->payload_flags & AV_PKT_FLAG_KEY);
01098         }
01099         av_freep(&ts_st->payload);
01100         av_freep(&ts_st->adts);
01101     }
01102     avio_flush(s->pb);
01103 
01104     for(i = 0; i < ts->nb_services; i++) {
01105         service = ts->services[i];
01106         av_freep(&service->provider_name);
01107         av_freep(&service->name);
01108         av_free(service);
01109     }
01110     av_free(ts->services);
01111 
01112     return 0;
01113 }
01114 
01115 AVOutputFormat ff_mpegts_muxer = {
01116     .name              = "mpegts",
01117     .long_name         = NULL_IF_CONFIG_SMALL("MPEG-2 transport stream format"),
01118     .mime_type         = "video/x-mpegts",
01119     .extensions        = "ts,m2t,m2ts,mts",
01120     .priv_data_size    = sizeof(MpegTSWrite),
01121     .audio_codec       = CODEC_ID_MP2,
01122     .video_codec       = CODEC_ID_MPEG2VIDEO,
01123     .write_header      = mpegts_write_header,
01124     .write_packet      = mpegts_write_packet,
01125     .write_trailer     = mpegts_write_end,
01126     .priv_class = &mpegts_muxer_class,
01127 };
Generated on Fri Feb 1 2013 14:34:53 for FFmpeg by doxygen 1.7.1