Libav 0.7.1
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00001 /* 00002 * FFM (ffserver live feed) demuxer 00003 * Copyright (c) 2001 Fabrice Bellard 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav 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 * Libav 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 Libav; 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/intreadwrite.h" 00023 #include "avformat.h" 00024 #include "ffm.h" 00025 #if CONFIG_FFSERVER 00026 #include <unistd.h> 00027 00028 int64_t ffm_read_write_index(int fd) 00029 { 00030 uint8_t buf[8]; 00031 00032 lseek(fd, 8, SEEK_SET); 00033 if (read(fd, buf, 8) != 8) 00034 return AVERROR(EIO); 00035 return AV_RB64(buf); 00036 } 00037 00038 int ffm_write_write_index(int fd, int64_t pos) 00039 { 00040 uint8_t buf[8]; 00041 int i; 00042 00043 for(i=0;i<8;i++) 00044 buf[i] = (pos >> (56 - i * 8)) & 0xff; 00045 lseek(fd, 8, SEEK_SET); 00046 if (write(fd, buf, 8) != 8) 00047 return AVERROR(EIO); 00048 return 8; 00049 } 00050 00051 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size) 00052 { 00053 FFMContext *ffm = s->priv_data; 00054 ffm->write_index = pos; 00055 ffm->file_size = file_size; 00056 } 00057 #endif // CONFIG_FFSERVER 00058 00059 static int ffm_is_avail_data(AVFormatContext *s, int size) 00060 { 00061 FFMContext *ffm = s->priv_data; 00062 int64_t pos, avail_size; 00063 int len; 00064 00065 len = ffm->packet_end - ffm->packet_ptr; 00066 if (size <= len) 00067 return 1; 00068 pos = avio_tell(s->pb); 00069 if (!ffm->write_index) { 00070 if (pos == ffm->file_size) 00071 return AVERROR_EOF; 00072 avail_size = ffm->file_size - pos; 00073 } else { 00074 if (pos == ffm->write_index) { 00075 /* exactly at the end of stream */ 00076 return AVERROR(EAGAIN); 00077 } else if (pos < ffm->write_index) { 00078 avail_size = ffm->write_index - pos; 00079 } else { 00080 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE); 00081 } 00082 } 00083 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len; 00084 if (size <= avail_size) 00085 return 1; 00086 else 00087 return AVERROR(EAGAIN); 00088 } 00089 00090 static int ffm_resync(AVFormatContext *s, int state) 00091 { 00092 av_log(s, AV_LOG_ERROR, "resyncing\n"); 00093 while (state != PACKET_ID) { 00094 if (s->pb->eof_reached) { 00095 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n"); 00096 return -1; 00097 } 00098 state = (state << 8) | avio_r8(s->pb); 00099 } 00100 return 0; 00101 } 00102 00103 /* first is true if we read the frame header */ 00104 static int ffm_read_data(AVFormatContext *s, 00105 uint8_t *buf, int size, int header) 00106 { 00107 FFMContext *ffm = s->priv_data; 00108 AVIOContext *pb = s->pb; 00109 int len, fill_size, size1, frame_offset, id; 00110 00111 size1 = size; 00112 while (size > 0) { 00113 redo: 00114 len = ffm->packet_end - ffm->packet_ptr; 00115 if (len < 0) 00116 return -1; 00117 if (len > size) 00118 len = size; 00119 if (len == 0) { 00120 if (avio_tell(pb) == ffm->file_size) 00121 avio_seek(pb, ffm->packet_size, SEEK_SET); 00122 retry_read: 00123 id = avio_rb16(pb); /* PACKET_ID */ 00124 if (id != PACKET_ID) 00125 if (ffm_resync(s, id) < 0) 00126 return -1; 00127 fill_size = avio_rb16(pb); 00128 ffm->dts = avio_rb64(pb); 00129 frame_offset = avio_rb16(pb); 00130 avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE); 00131 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size); 00132 if (ffm->packet_end < ffm->packet || frame_offset < 0) 00133 return -1; 00134 /* if first packet or resynchronization packet, we must 00135 handle it specifically */ 00136 if (ffm->first_packet || (frame_offset & 0x8000)) { 00137 if (!frame_offset) { 00138 /* This packet has no frame headers in it */ 00139 if (avio_tell(pb) >= ffm->packet_size * 3) { 00140 avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR); 00141 goto retry_read; 00142 } 00143 /* This is bad, we cannot find a valid frame header */ 00144 return 0; 00145 } 00146 ffm->first_packet = 0; 00147 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE) 00148 return -1; 00149 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE; 00150 if (!header) 00151 break; 00152 } else { 00153 ffm->packet_ptr = ffm->packet; 00154 } 00155 goto redo; 00156 } 00157 memcpy(buf, ffm->packet_ptr, len); 00158 buf += len; 00159 ffm->packet_ptr += len; 00160 size -= len; 00161 header = 0; 00162 } 00163 return size1 - size; 00164 } 00165 00166 /* ensure that acutal seeking happens between FFM_PACKET_SIZE 00167 and file_size - FFM_PACKET_SIZE */ 00168 static void ffm_seek1(AVFormatContext *s, int64_t pos1) 00169 { 00170 FFMContext *ffm = s->priv_data; 00171 AVIOContext *pb = s->pb; 00172 int64_t pos; 00173 00174 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE); 00175 pos = FFMAX(pos, FFM_PACKET_SIZE); 00176 av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos); 00177 avio_seek(pb, pos, SEEK_SET); 00178 } 00179 00180 static int64_t get_dts(AVFormatContext *s, int64_t pos) 00181 { 00182 AVIOContext *pb = s->pb; 00183 int64_t dts; 00184 00185 ffm_seek1(s, pos); 00186 avio_skip(pb, 4); 00187 dts = avio_rb64(pb); 00188 av_dlog(s, "dts=%0.6f\n", dts / 1000000.0); 00189 return dts; 00190 } 00191 00192 static void adjust_write_index(AVFormatContext *s) 00193 { 00194 FFMContext *ffm = s->priv_data; 00195 AVIOContext *pb = s->pb; 00196 int64_t pts; 00197 //int64_t orig_write_index = ffm->write_index; 00198 int64_t pos_min, pos_max; 00199 int64_t pts_start; 00200 int64_t ptr = avio_tell(pb); 00201 00202 00203 pos_min = 0; 00204 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE; 00205 00206 pts_start = get_dts(s, pos_min); 00207 00208 pts = get_dts(s, pos_max); 00209 00210 if (pts - 100000 > pts_start) 00211 goto end; 00212 00213 ffm->write_index = FFM_PACKET_SIZE; 00214 00215 pts_start = get_dts(s, pos_min); 00216 00217 pts = get_dts(s, pos_max); 00218 00219 if (pts - 100000 <= pts_start) { 00220 while (1) { 00221 int64_t newpos; 00222 int64_t newpts; 00223 00224 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE; 00225 00226 if (newpos == pos_min) 00227 break; 00228 00229 newpts = get_dts(s, newpos); 00230 00231 if (newpts - 100000 <= pts) { 00232 pos_max = newpos; 00233 pts = newpts; 00234 } else { 00235 pos_min = newpos; 00236 } 00237 } 00238 ffm->write_index += pos_max; 00239 } 00240 00241 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.); 00242 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. ); 00243 00244 end: 00245 avio_seek(pb, ptr, SEEK_SET); 00246 } 00247 00248 00249 static int ffm_close(AVFormatContext *s) 00250 { 00251 int i; 00252 00253 for (i = 0; i < s->nb_streams; i++) 00254 av_freep(&s->streams[i]->codec->rc_eq); 00255 00256 return 0; 00257 } 00258 00259 00260 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap) 00261 { 00262 FFMContext *ffm = s->priv_data; 00263 AVStream *st; 00264 AVIOContext *pb = s->pb; 00265 AVCodecContext *codec; 00266 int i, nb_streams; 00267 uint32_t tag; 00268 00269 /* header */ 00270 tag = avio_rl32(pb); 00271 if (tag != MKTAG('F', 'F', 'M', '1')) 00272 goto fail; 00273 ffm->packet_size = avio_rb32(pb); 00274 if (ffm->packet_size != FFM_PACKET_SIZE) 00275 goto fail; 00276 ffm->write_index = avio_rb64(pb); 00277 /* get also filesize */ 00278 if (pb->seekable) { 00279 ffm->file_size = avio_size(pb); 00280 if (ffm->write_index) 00281 adjust_write_index(s); 00282 } else { 00283 ffm->file_size = (UINT64_C(1) << 63) - 1; 00284 } 00285 00286 nb_streams = avio_rb32(pb); 00287 avio_rb32(pb); /* total bitrate */ 00288 /* read each stream */ 00289 for(i=0;i<nb_streams;i++) { 00290 char rc_eq_buf[128]; 00291 00292 st = av_new_stream(s, 0); 00293 if (!st) 00294 goto fail; 00295 00296 av_set_pts_info(st, 64, 1, 1000000); 00297 00298 codec = st->codec; 00299 /* generic info */ 00300 codec->codec_id = avio_rb32(pb); 00301 codec->codec_type = avio_r8(pb); /* codec_type */ 00302 codec->bit_rate = avio_rb32(pb); 00303 st->quality = avio_rb32(pb); 00304 codec->flags = avio_rb32(pb); 00305 codec->flags2 = avio_rb32(pb); 00306 codec->debug = avio_rb32(pb); 00307 /* specific info */ 00308 switch(codec->codec_type) { 00309 case AVMEDIA_TYPE_VIDEO: 00310 codec->time_base.num = avio_rb32(pb); 00311 codec->time_base.den = avio_rb32(pb); 00312 codec->width = avio_rb16(pb); 00313 codec->height = avio_rb16(pb); 00314 codec->gop_size = avio_rb16(pb); 00315 codec->pix_fmt = avio_rb32(pb); 00316 codec->qmin = avio_r8(pb); 00317 codec->qmax = avio_r8(pb); 00318 codec->max_qdiff = avio_r8(pb); 00319 codec->qcompress = avio_rb16(pb) / 10000.0; 00320 codec->qblur = avio_rb16(pb) / 10000.0; 00321 codec->bit_rate_tolerance = avio_rb32(pb); 00322 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf)); 00323 codec->rc_eq = av_strdup(rc_eq_buf); 00324 codec->rc_max_rate = avio_rb32(pb); 00325 codec->rc_min_rate = avio_rb32(pb); 00326 codec->rc_buffer_size = avio_rb32(pb); 00327 codec->i_quant_factor = av_int2dbl(avio_rb64(pb)); 00328 codec->b_quant_factor = av_int2dbl(avio_rb64(pb)); 00329 codec->i_quant_offset = av_int2dbl(avio_rb64(pb)); 00330 codec->b_quant_offset = av_int2dbl(avio_rb64(pb)); 00331 codec->dct_algo = avio_rb32(pb); 00332 codec->strict_std_compliance = avio_rb32(pb); 00333 codec->max_b_frames = avio_rb32(pb); 00334 codec->luma_elim_threshold = avio_rb32(pb); 00335 codec->chroma_elim_threshold = avio_rb32(pb); 00336 codec->mpeg_quant = avio_rb32(pb); 00337 codec->intra_dc_precision = avio_rb32(pb); 00338 codec->me_method = avio_rb32(pb); 00339 codec->mb_decision = avio_rb32(pb); 00340 codec->nsse_weight = avio_rb32(pb); 00341 codec->frame_skip_cmp = avio_rb32(pb); 00342 codec->rc_buffer_aggressivity = av_int2dbl(avio_rb64(pb)); 00343 codec->codec_tag = avio_rb32(pb); 00344 codec->thread_count = avio_r8(pb); 00345 codec->coder_type = avio_rb32(pb); 00346 codec->me_cmp = avio_rb32(pb); 00347 codec->partitions = avio_rb32(pb); 00348 codec->me_subpel_quality = avio_rb32(pb); 00349 codec->me_range = avio_rb32(pb); 00350 codec->keyint_min = avio_rb32(pb); 00351 codec->scenechange_threshold = avio_rb32(pb); 00352 codec->b_frame_strategy = avio_rb32(pb); 00353 codec->qcompress = av_int2dbl(avio_rb64(pb)); 00354 codec->qblur = av_int2dbl(avio_rb64(pb)); 00355 codec->max_qdiff = avio_rb32(pb); 00356 codec->refs = avio_rb32(pb); 00357 codec->directpred = avio_rb32(pb); 00358 break; 00359 case AVMEDIA_TYPE_AUDIO: 00360 codec->sample_rate = avio_rb32(pb); 00361 codec->channels = avio_rl16(pb); 00362 codec->frame_size = avio_rl16(pb); 00363 codec->sample_fmt = (int16_t) avio_rl16(pb); 00364 break; 00365 default: 00366 goto fail; 00367 } 00368 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) { 00369 codec->extradata_size = avio_rb32(pb); 00370 codec->extradata = av_malloc(codec->extradata_size); 00371 if (!codec->extradata) 00372 return AVERROR(ENOMEM); 00373 avio_read(pb, codec->extradata, codec->extradata_size); 00374 } 00375 } 00376 00377 /* get until end of block reached */ 00378 while ((avio_tell(pb) % ffm->packet_size) != 0) 00379 avio_r8(pb); 00380 00381 /* init packet demux */ 00382 ffm->packet_ptr = ffm->packet; 00383 ffm->packet_end = ffm->packet; 00384 ffm->frame_offset = 0; 00385 ffm->dts = 0; 00386 ffm->read_state = READ_HEADER; 00387 ffm->first_packet = 1; 00388 return 0; 00389 fail: 00390 ffm_close(s); 00391 return -1; 00392 } 00393 00394 /* return < 0 if eof */ 00395 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt) 00396 { 00397 int size; 00398 FFMContext *ffm = s->priv_data; 00399 int duration, ret; 00400 00401 switch(ffm->read_state) { 00402 case READ_HEADER: 00403 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0) 00404 return ret; 00405 00406 av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n", 00407 avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size); 00408 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != 00409 FRAME_HEADER_SIZE) 00410 return -1; 00411 if (ffm->header[1] & FLAG_DTS) 00412 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4) 00413 return -1; 00414 ffm->read_state = READ_DATA; 00415 /* fall thru */ 00416 case READ_DATA: 00417 size = AV_RB24(ffm->header + 2); 00418 if ((ret = ffm_is_avail_data(s, size)) < 0) 00419 return ret; 00420 00421 duration = AV_RB24(ffm->header + 5); 00422 00423 av_new_packet(pkt, size); 00424 pkt->stream_index = ffm->header[0]; 00425 if ((unsigned)pkt->stream_index >= s->nb_streams) { 00426 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index); 00427 av_free_packet(pkt); 00428 ffm->read_state = READ_HEADER; 00429 return -1; 00430 } 00431 pkt->pos = avio_tell(s->pb); 00432 if (ffm->header[1] & FLAG_KEY_FRAME) 00433 pkt->flags |= AV_PKT_FLAG_KEY; 00434 00435 ffm->read_state = READ_HEADER; 00436 if (ffm_read_data(s, pkt->data, size, 0) != size) { 00437 /* bad case: desynchronized packet. we cancel all the packet loading */ 00438 av_free_packet(pkt); 00439 return -1; 00440 } 00441 pkt->pts = AV_RB64(ffm->header+8); 00442 if (ffm->header[1] & FLAG_DTS) 00443 pkt->dts = pkt->pts - AV_RB32(ffm->header+16); 00444 else 00445 pkt->dts = pkt->pts; 00446 pkt->duration = duration; 00447 break; 00448 } 00449 return 0; 00450 } 00451 00452 /* seek to a given time in the file. The file read pointer is 00453 positioned at or before pts. XXX: the following code is quite 00454 approximative */ 00455 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags) 00456 { 00457 FFMContext *ffm = s->priv_data; 00458 int64_t pos_min, pos_max, pos; 00459 int64_t pts_min, pts_max, pts; 00460 double pos1; 00461 00462 av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0); 00463 /* find the position using linear interpolation (better than 00464 dichotomy in typical cases) */ 00465 pos_min = FFM_PACKET_SIZE; 00466 pos_max = ffm->file_size - FFM_PACKET_SIZE; 00467 while (pos_min <= pos_max) { 00468 pts_min = get_dts(s, pos_min); 00469 pts_max = get_dts(s, pos_max); 00470 /* linear interpolation */ 00471 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) / 00472 (double)(pts_max - pts_min); 00473 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE; 00474 if (pos <= pos_min) 00475 pos = pos_min; 00476 else if (pos >= pos_max) 00477 pos = pos_max; 00478 pts = get_dts(s, pos); 00479 /* check if we are lucky */ 00480 if (pts == wanted_pts) { 00481 goto found; 00482 } else if (pts > wanted_pts) { 00483 pos_max = pos - FFM_PACKET_SIZE; 00484 } else { 00485 pos_min = pos + FFM_PACKET_SIZE; 00486 } 00487 } 00488 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max; 00489 00490 found: 00491 ffm_seek1(s, pos); 00492 00493 /* reset read state */ 00494 ffm->read_state = READ_HEADER; 00495 ffm->packet_ptr = ffm->packet; 00496 ffm->packet_end = ffm->packet; 00497 ffm->first_packet = 1; 00498 00499 return 0; 00500 } 00501 00502 static int ffm_probe(AVProbeData *p) 00503 { 00504 if ( 00505 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' && 00506 p->buf[3] == '1') 00507 return AVPROBE_SCORE_MAX + 1; 00508 return 0; 00509 } 00510 00511 AVInputFormat ff_ffm_demuxer = { 00512 "ffm", 00513 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"), 00514 sizeof(FFMContext), 00515 ffm_probe, 00516 ffm_read_header, 00517 ffm_read_packet, 00518 ffm_close, 00519 ffm_seek, 00520 };