2 * FFM (ffserver live feed) demuxer
3 * Copyright (c) 2001 Fabrice Bellard.
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
28 int64_t ffm_read_write_index(int fd)
32 lseek(fd, 8, SEEK_SET);
37 void ffm_write_write_index(int fd, int64_t pos)
43 buf[i] = (pos >> (56 - i * 8)) & 0xff;
44 lseek(fd, 8, SEEK_SET);
48 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
50 FFMContext *ffm = s->priv_data;
51 ffm->write_index = pos;
52 ffm->file_size = file_size;
54 #endif // CONFIG_FFSERVER
56 static int ffm_is_avail_data(AVFormatContext *s, int size)
58 FFMContext *ffm = s->priv_data;
59 int64_t pos, avail_size;
62 len = ffm->packet_end - ffm->packet_ptr;
65 pos = url_ftell(s->pb);
66 if (pos == ffm->write_index) {
67 /* exactly at the end of stream */
69 } else if (pos < ffm->write_index) {
70 avail_size = ffm->write_index - pos;
72 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
74 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
75 if (size <= avail_size)
81 /* first is true if we read the frame header */
82 static int ffm_read_data(AVFormatContext *s,
83 uint8_t *buf, int size, int header)
85 FFMContext *ffm = s->priv_data;
86 ByteIOContext *pb = s->pb;
87 int len, fill_size, size1, frame_offset;
92 len = ffm->packet_end - ffm->packet_ptr;
98 if (url_ftell(pb) == ffm->file_size)
99 url_fseek(pb, ffm->packet_size, SEEK_SET);
101 get_be16(pb); /* PACKET_ID */
102 fill_size = get_be16(pb);
103 ffm->dts = get_be64(pb);
104 frame_offset = get_be16(pb);
105 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
106 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
107 if (ffm->packet_end < ffm->packet || frame_offset < 0)
109 /* if first packet or resynchronization packet, we must
110 handle it specifically */
111 if (ffm->first_packet || (frame_offset & 0x8000)) {
113 /* This packet has no frame headers in it */
114 if (url_ftell(pb) >= ffm->packet_size * 3) {
115 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
118 /* This is bad, we cannot find a valid frame header */
121 ffm->first_packet = 0;
122 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
124 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
128 ffm->packet_ptr = ffm->packet;
132 memcpy(buf, ffm->packet_ptr, len);
134 ffm->packet_ptr += len;
143 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
144 by the write position inside this function */
145 static void ffm_seek1(AVFormatContext *s, int64_t pos1)
147 FFMContext *ffm = s->priv_data;
148 ByteIOContext *pb = s->pb;
151 pos = pos1 + ffm->write_index;
152 if (pos >= ffm->file_size)
153 pos -= (ffm->file_size - FFM_PACKET_SIZE);
155 av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
157 url_fseek(pb, pos, SEEK_SET);
160 static int64_t get_dts(AVFormatContext *s, int64_t pos)
162 ByteIOContext *pb = s->pb;
169 av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
174 static void adjust_write_index(AVFormatContext *s)
176 FFMContext *ffm = s->priv_data;
177 ByteIOContext *pb = s->pb;
179 //int64_t orig_write_index = ffm->write_index;
180 int64_t pos_min, pos_max;
182 int64_t ptr = url_ftell(pb);
186 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
188 pts_start = get_dts(s, pos_min);
190 pts = get_dts(s, pos_max);
192 if (pts - 100000 > pts_start)
195 ffm->write_index = FFM_PACKET_SIZE;
197 pts_start = get_dts(s, pos_min);
199 pts = get_dts(s, pos_max);
201 if (pts - 100000 <= pts_start) {
206 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
208 if (newpos == pos_min)
211 newpts = get_dts(s, newpos);
213 if (newpts - 100000 <= pts) {
220 ffm->write_index += pos_max;
223 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
224 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
227 url_fseek(pb, ptr, SEEK_SET);
231 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
233 FFMContext *ffm = s->priv_data;
235 ByteIOContext *pb = s->pb;
236 AVCodecContext *codec;
242 if (tag != MKTAG('F', 'F', 'M', '1'))
244 ffm->packet_size = get_be32(pb);
245 if (ffm->packet_size != FFM_PACKET_SIZE)
247 ffm->write_index = get_be64(pb);
248 /* get also filesize */
249 if (!url_is_streamed(pb)) {
250 ffm->file_size = url_fsize(pb);
251 adjust_write_index(s);
253 ffm->file_size = (UINT64_C(1) << 63) - 1;
256 nb_streams = get_be32(pb);
257 get_be32(pb); /* total bitrate */
258 /* read each stream */
259 for(i=0;i<nb_streams;i++) {
262 st = av_new_stream(s, 0);
267 av_set_pts_info(st, 64, 1, 1000000);
271 codec->codec_id = get_be32(pb);
272 codec->codec_type = get_byte(pb); /* codec_type */
273 codec->bit_rate = get_be32(pb);
274 st->quality = get_be32(pb);
275 codec->flags = get_be32(pb);
276 codec->flags2 = get_be32(pb);
277 codec->debug = get_be32(pb);
279 switch(codec->codec_type) {
280 case CODEC_TYPE_VIDEO:
281 codec->time_base.num = get_be32(pb);
282 codec->time_base.den = get_be32(pb);
283 codec->width = get_be16(pb);
284 codec->height = get_be16(pb);
285 codec->gop_size = get_be16(pb);
286 codec->pix_fmt = get_be32(pb);
287 codec->qmin = get_byte(pb);
288 codec->qmax = get_byte(pb);
289 codec->max_qdiff = get_byte(pb);
290 codec->qcompress = get_be16(pb) / 10000.0;
291 codec->qblur = get_be16(pb) / 10000.0;
292 codec->bit_rate_tolerance = get_be32(pb);
293 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
294 codec->rc_max_rate = get_be32(pb);
295 codec->rc_min_rate = get_be32(pb);
296 codec->rc_buffer_size = get_be32(pb);
297 codec->i_quant_factor = av_int2dbl(get_be64(pb));
298 codec->b_quant_factor = av_int2dbl(get_be64(pb));
299 codec->i_quant_offset = av_int2dbl(get_be64(pb));
300 codec->b_quant_offset = av_int2dbl(get_be64(pb));
301 codec->dct_algo = get_be32(pb);
302 codec->strict_std_compliance = get_be32(pb);
303 codec->max_b_frames = get_be32(pb);
304 codec->luma_elim_threshold = get_be32(pb);
305 codec->chroma_elim_threshold = get_be32(pb);
306 codec->mpeg_quant = get_be32(pb);
307 codec->intra_dc_precision = get_be32(pb);
308 codec->me_method = get_be32(pb);
309 codec->mb_decision = get_be32(pb);
310 codec->nsse_weight = get_be32(pb);
311 codec->frame_skip_cmp = get_be32(pb);
312 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
313 codec->codec_tag = get_be32(pb);
314 codec->thread_count = get_byte(pb);
316 case CODEC_TYPE_AUDIO:
317 codec->sample_rate = get_be32(pb);
318 codec->channels = get_le16(pb);
319 codec->frame_size = get_le16(pb);
324 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
325 codec->extradata_size = get_be32(pb);
326 codec->extradata = av_malloc(codec->extradata_size);
327 if (!codec->extradata)
328 return AVERROR(ENOMEM);
329 get_buffer(pb, codec->extradata, codec->extradata_size);
333 /* get until end of block reached */
334 while ((url_ftell(pb) % ffm->packet_size) != 0)
337 /* init packet demux */
338 ffm->packet_ptr = ffm->packet;
339 ffm->packet_end = ffm->packet;
340 ffm->frame_offset = 0;
342 ffm->read_state = READ_HEADER;
343 ffm->first_packet = 1;
346 for(i=0;i<s->nb_streams;i++) {
355 /* return < 0 if eof */
356 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
359 FFMContext *ffm = s->priv_data;
362 switch(ffm->read_state) {
364 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) {
365 return AVERROR(EAGAIN);
367 dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
368 url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
369 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
371 return AVERROR(EAGAIN);
372 if (ffm->header[1] & FLAG_DTS)
373 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
374 return AVERROR(EAGAIN);
376 av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
378 ffm->read_state = READ_DATA;
381 size = AV_RB24(ffm->header + 2);
382 if (!ffm_is_avail_data(s, size)) {
383 return AVERROR(EAGAIN);
386 duration = AV_RB24(ffm->header + 5);
388 av_new_packet(pkt, size);
389 pkt->stream_index = ffm->header[0];
390 if ((unsigned)pkt->stream_index >= s->nb_streams) {
391 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
393 ffm->read_state = READ_HEADER;
394 return AVERROR(EAGAIN);
396 pkt->pos = url_ftell(s->pb);
397 if (ffm->header[1] & FLAG_KEY_FRAME)
398 pkt->flags |= PKT_FLAG_KEY;
400 ffm->read_state = READ_HEADER;
401 if (ffm_read_data(s, pkt->data, size, 0) != size) {
402 /* bad case: desynchronized packet. we cancel all the packet loading */
404 return AVERROR(EAGAIN);
406 pkt->pts = AV_RB64(ffm->header+8);
407 if (ffm->header[1] & FLAG_DTS)
408 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
411 pkt->duration = duration;
417 /* seek to a given time in the file. The file read pointer is
418 positioned at or before pts. XXX: the following code is quite
420 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
422 FFMContext *ffm = s->priv_data;
423 int64_t pos_min, pos_max, pos;
424 int64_t pts_min, pts_max, pts;
428 av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
430 /* find the position using linear interpolation (better than
431 dichotomy in typical cases) */
433 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
434 while (pos_min <= pos_max) {
435 pts_min = get_dts(s, pos_min);
436 pts_max = get_dts(s, pos_max);
437 /* linear interpolation */
438 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
439 (double)(pts_max - pts_min);
440 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
443 else if (pos >= pos_max)
445 pts = get_dts(s, pos);
446 /* check if we are lucky */
447 if (pts == wanted_pts) {
449 } else if (pts > wanted_pts) {
450 pos_max = pos - FFM_PACKET_SIZE;
452 pos_min = pos + FFM_PACKET_SIZE;
455 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
457 pos -= FFM_PACKET_SIZE;
461 /* reset read state */
462 ffm->read_state = READ_HEADER;
463 ffm->packet_ptr = ffm->packet;
464 ffm->packet_end = ffm->packet;
465 ffm->first_packet = 1;
470 static int ffm_probe(AVProbeData *p)
473 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
475 return AVPROBE_SCORE_MAX + 1;
479 AVInputFormat ffm_demuxer = {
481 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),