Libav
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00001 /* 00002 * FFM (ffserver live feed) demuxer 00003 * Copyright (c) 2001 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/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 = url_ftell(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 (url_feof(s->pb)) { 00095 av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n"); 00096 return -1; 00097 } 00098 state = (state << 8) | get_byte(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 ByteIOContext *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 (url_ftell(pb) == ffm->file_size) 00121 url_fseek(pb, ffm->packet_size, SEEK_SET); 00122 retry_read: 00123 id = get_be16(pb); /* PACKET_ID */ 00124 if (id != PACKET_ID) 00125 if (ffm_resync(s, id) < 0) 00126 return -1; 00127 fill_size = get_be16(pb); 00128 ffm->dts = get_be64(pb); 00129 frame_offset = get_be16(pb); 00130 get_buffer(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 (url_ftell(pb) >= ffm->packet_size * 3) { 00140 url_fseek(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 //#define DEBUG_SEEK 00167 00168 /* ensure that acutal seeking happens between FFM_PACKET_SIZE 00169 and file_size - FFM_PACKET_SIZE */ 00170 static void ffm_seek1(AVFormatContext *s, int64_t pos1) 00171 { 00172 FFMContext *ffm = s->priv_data; 00173 ByteIOContext *pb = s->pb; 00174 int64_t pos; 00175 00176 pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE); 00177 pos = FFMAX(pos, FFM_PACKET_SIZE); 00178 #ifdef DEBUG_SEEK 00179 av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos); 00180 #endif 00181 url_fseek(pb, pos, SEEK_SET); 00182 } 00183 00184 static int64_t get_dts(AVFormatContext *s, int64_t pos) 00185 { 00186 ByteIOContext *pb = s->pb; 00187 int64_t dts; 00188 00189 ffm_seek1(s, pos); 00190 url_fskip(pb, 4); 00191 dts = get_be64(pb); 00192 #ifdef DEBUG_SEEK 00193 av_log(s, AV_LOG_DEBUG, "dts=%0.6f\n", dts / 1000000.0); 00194 #endif 00195 return dts; 00196 } 00197 00198 static void adjust_write_index(AVFormatContext *s) 00199 { 00200 FFMContext *ffm = s->priv_data; 00201 ByteIOContext *pb = s->pb; 00202 int64_t pts; 00203 //int64_t orig_write_index = ffm->write_index; 00204 int64_t pos_min, pos_max; 00205 int64_t pts_start; 00206 int64_t ptr = url_ftell(pb); 00207 00208 00209 pos_min = 0; 00210 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE; 00211 00212 pts_start = get_dts(s, pos_min); 00213 00214 pts = get_dts(s, pos_max); 00215 00216 if (pts - 100000 > pts_start) 00217 goto end; 00218 00219 ffm->write_index = FFM_PACKET_SIZE; 00220 00221 pts_start = get_dts(s, pos_min); 00222 00223 pts = get_dts(s, pos_max); 00224 00225 if (pts - 100000 <= pts_start) { 00226 while (1) { 00227 int64_t newpos; 00228 int64_t newpts; 00229 00230 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE; 00231 00232 if (newpos == pos_min) 00233 break; 00234 00235 newpts = get_dts(s, newpos); 00236 00237 if (newpts - 100000 <= pts) { 00238 pos_max = newpos; 00239 pts = newpts; 00240 } else { 00241 pos_min = newpos; 00242 } 00243 } 00244 ffm->write_index += pos_max; 00245 } 00246 00247 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.); 00248 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. ); 00249 00250 end: 00251 url_fseek(pb, ptr, SEEK_SET); 00252 } 00253 00254 00255 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap) 00256 { 00257 FFMContext *ffm = s->priv_data; 00258 AVStream *st; 00259 ByteIOContext *pb = s->pb; 00260 AVCodecContext *codec; 00261 int i, nb_streams; 00262 uint32_t tag; 00263 00264 /* header */ 00265 tag = get_le32(pb); 00266 if (tag != MKTAG('F', 'F', 'M', '1')) 00267 goto fail; 00268 ffm->packet_size = get_be32(pb); 00269 if (ffm->packet_size != FFM_PACKET_SIZE) 00270 goto fail; 00271 ffm->write_index = get_be64(pb); 00272 /* get also filesize */ 00273 if (!url_is_streamed(pb)) { 00274 ffm->file_size = url_fsize(pb); 00275 if (ffm->write_index) 00276 adjust_write_index(s); 00277 } else { 00278 ffm->file_size = (UINT64_C(1) << 63) - 1; 00279 } 00280 00281 nb_streams = get_be32(pb); 00282 get_be32(pb); /* total bitrate */ 00283 /* read each stream */ 00284 for(i=0;i<nb_streams;i++) { 00285 char rc_eq_buf[128]; 00286 00287 st = av_new_stream(s, 0); 00288 if (!st) 00289 goto fail; 00290 00291 av_set_pts_info(st, 64, 1, 1000000); 00292 00293 codec = st->codec; 00294 /* generic info */ 00295 codec->codec_id = get_be32(pb); 00296 codec->codec_type = get_byte(pb); /* codec_type */ 00297 codec->bit_rate = get_be32(pb); 00298 st->quality = get_be32(pb); 00299 codec->flags = get_be32(pb); 00300 codec->flags2 = get_be32(pb); 00301 codec->debug = get_be32(pb); 00302 /* specific info */ 00303 switch(codec->codec_type) { 00304 case AVMEDIA_TYPE_VIDEO: 00305 codec->time_base.num = get_be32(pb); 00306 codec->time_base.den = get_be32(pb); 00307 codec->width = get_be16(pb); 00308 codec->height = get_be16(pb); 00309 codec->gop_size = get_be16(pb); 00310 codec->pix_fmt = get_be32(pb); 00311 codec->qmin = get_byte(pb); 00312 codec->qmax = get_byte(pb); 00313 codec->max_qdiff = get_byte(pb); 00314 codec->qcompress = get_be16(pb) / 10000.0; 00315 codec->qblur = get_be16(pb) / 10000.0; 00316 codec->bit_rate_tolerance = get_be32(pb); 00317 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf))); 00318 codec->rc_max_rate = get_be32(pb); 00319 codec->rc_min_rate = get_be32(pb); 00320 codec->rc_buffer_size = get_be32(pb); 00321 codec->i_quant_factor = av_int2dbl(get_be64(pb)); 00322 codec->b_quant_factor = av_int2dbl(get_be64(pb)); 00323 codec->i_quant_offset = av_int2dbl(get_be64(pb)); 00324 codec->b_quant_offset = av_int2dbl(get_be64(pb)); 00325 codec->dct_algo = get_be32(pb); 00326 codec->strict_std_compliance = get_be32(pb); 00327 codec->max_b_frames = get_be32(pb); 00328 codec->luma_elim_threshold = get_be32(pb); 00329 codec->chroma_elim_threshold = get_be32(pb); 00330 codec->mpeg_quant = get_be32(pb); 00331 codec->intra_dc_precision = get_be32(pb); 00332 codec->me_method = get_be32(pb); 00333 codec->mb_decision = get_be32(pb); 00334 codec->nsse_weight = get_be32(pb); 00335 codec->frame_skip_cmp = get_be32(pb); 00336 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb)); 00337 codec->codec_tag = get_be32(pb); 00338 codec->thread_count = get_byte(pb); 00339 codec->coder_type = get_be32(pb); 00340 codec->me_cmp = get_be32(pb); 00341 codec->partitions = get_be32(pb); 00342 codec->me_subpel_quality = get_be32(pb); 00343 codec->me_range = get_be32(pb); 00344 codec->keyint_min = get_be32(pb); 00345 codec->scenechange_threshold = get_be32(pb); 00346 codec->b_frame_strategy = get_be32(pb); 00347 codec->qcompress = av_int2dbl(get_be64(pb)); 00348 codec->qblur = av_int2dbl(get_be64(pb)); 00349 codec->max_qdiff = get_be32(pb); 00350 codec->refs = get_be32(pb); 00351 codec->directpred = get_be32(pb); 00352 break; 00353 case AVMEDIA_TYPE_AUDIO: 00354 codec->sample_rate = get_be32(pb); 00355 codec->channels = get_le16(pb); 00356 codec->frame_size = get_le16(pb); 00357 codec->sample_fmt = (int16_t) get_le16(pb); 00358 break; 00359 default: 00360 goto fail; 00361 } 00362 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) { 00363 codec->extradata_size = get_be32(pb); 00364 codec->extradata = av_malloc(codec->extradata_size); 00365 if (!codec->extradata) 00366 return AVERROR(ENOMEM); 00367 get_buffer(pb, codec->extradata, codec->extradata_size); 00368 } 00369 } 00370 00371 /* get until end of block reached */ 00372 while ((url_ftell(pb) % ffm->packet_size) != 0) 00373 get_byte(pb); 00374 00375 /* init packet demux */ 00376 ffm->packet_ptr = ffm->packet; 00377 ffm->packet_end = ffm->packet; 00378 ffm->frame_offset = 0; 00379 ffm->dts = 0; 00380 ffm->read_state = READ_HEADER; 00381 ffm->first_packet = 1; 00382 return 0; 00383 fail: 00384 for(i=0;i<s->nb_streams;i++) { 00385 st = s->streams[i]; 00386 if (st) { 00387 av_free(st); 00388 } 00389 } 00390 return -1; 00391 } 00392 00393 /* return < 0 if eof */ 00394 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt) 00395 { 00396 int size; 00397 FFMContext *ffm = s->priv_data; 00398 int duration, ret; 00399 00400 switch(ffm->read_state) { 00401 case READ_HEADER: 00402 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0) 00403 return ret; 00404 00405 dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n", 00406 url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size); 00407 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != 00408 FRAME_HEADER_SIZE) 00409 return -1; 00410 if (ffm->header[1] & FLAG_DTS) 00411 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4) 00412 return -1; 00413 #if 0 00414 av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE); 00415 #endif 00416 ffm->read_state = READ_DATA; 00417 /* fall thru */ 00418 case READ_DATA: 00419 size = AV_RB24(ffm->header + 2); 00420 if ((ret = ffm_is_avail_data(s, size)) < 0) 00421 return ret; 00422 00423 duration = AV_RB24(ffm->header + 5); 00424 00425 av_new_packet(pkt, size); 00426 pkt->stream_index = ffm->header[0]; 00427 if ((unsigned)pkt->stream_index >= s->nb_streams) { 00428 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index); 00429 av_free_packet(pkt); 00430 ffm->read_state = READ_HEADER; 00431 return -1; 00432 } 00433 pkt->pos = url_ftell(s->pb); 00434 if (ffm->header[1] & FLAG_KEY_FRAME) 00435 pkt->flags |= AV_PKT_FLAG_KEY; 00436 00437 ffm->read_state = READ_HEADER; 00438 if (ffm_read_data(s, pkt->data, size, 0) != size) { 00439 /* bad case: desynchronized packet. we cancel all the packet loading */ 00440 av_free_packet(pkt); 00441 return -1; 00442 } 00443 pkt->pts = AV_RB64(ffm->header+8); 00444 if (ffm->header[1] & FLAG_DTS) 00445 pkt->dts = pkt->pts - AV_RB32(ffm->header+16); 00446 else 00447 pkt->dts = pkt->pts; 00448 pkt->duration = duration; 00449 break; 00450 } 00451 return 0; 00452 } 00453 00454 /* seek to a given time in the file. The file read pointer is 00455 positioned at or before pts. XXX: the following code is quite 00456 approximative */ 00457 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags) 00458 { 00459 FFMContext *ffm = s->priv_data; 00460 int64_t pos_min, pos_max, pos; 00461 int64_t pts_min, pts_max, pts; 00462 double pos1; 00463 00464 #ifdef DEBUG_SEEK 00465 av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0); 00466 #endif 00467 /* find the position using linear interpolation (better than 00468 dichotomy in typical cases) */ 00469 pos_min = FFM_PACKET_SIZE; 00470 pos_max = ffm->file_size - FFM_PACKET_SIZE; 00471 while (pos_min <= pos_max) { 00472 pts_min = get_dts(s, pos_min); 00473 pts_max = get_dts(s, pos_max); 00474 /* linear interpolation */ 00475 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) / 00476 (double)(pts_max - pts_min); 00477 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE; 00478 if (pos <= pos_min) 00479 pos = pos_min; 00480 else if (pos >= pos_max) 00481 pos = pos_max; 00482 pts = get_dts(s, pos); 00483 /* check if we are lucky */ 00484 if (pts == wanted_pts) { 00485 goto found; 00486 } else if (pts > wanted_pts) { 00487 pos_max = pos - FFM_PACKET_SIZE; 00488 } else { 00489 pos_min = pos + FFM_PACKET_SIZE; 00490 } 00491 } 00492 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max; 00493 00494 found: 00495 ffm_seek1(s, pos); 00496 00497 /* reset read state */ 00498 ffm->read_state = READ_HEADER; 00499 ffm->packet_ptr = ffm->packet; 00500 ffm->packet_end = ffm->packet; 00501 ffm->first_packet = 1; 00502 00503 return 0; 00504 } 00505 00506 static int ffm_probe(AVProbeData *p) 00507 { 00508 if ( 00509 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' && 00510 p->buf[3] == '1') 00511 return AVPROBE_SCORE_MAX + 1; 00512 return 0; 00513 } 00514 00515 static int ffm_close(AVFormatContext *s) 00516 { 00517 int i; 00518 00519 for (i = 0; i < s->nb_streams; i++) 00520 av_freep(&s->streams[i]->codec->rc_eq); 00521 00522 return 0; 00523 } 00524 00525 AVInputFormat ffm_demuxer = { 00526 "ffm", 00527 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"), 00528 sizeof(FFMContext), 00529 ffm_probe, 00530 ffm_read_header, 00531 ffm_read_packet, 00532 ffm_close, 00533 ffm_seek, 00534 };