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);
33 if (read(fd, buf, 8) != 8)
38 int ffm_write_write_index(int fd, int64_t pos)
44 buf[i] = (pos >> (56 - i * 8)) & 0xff;
45 lseek(fd, 8, SEEK_SET);
46 if (write(fd, buf, 8) != 8)
51 void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
53 FFMContext *ffm = s->priv_data;
54 ffm->write_index = pos;
55 ffm->file_size = file_size;
57 #endif // CONFIG_FFSERVER
59 static int ffm_is_avail_data(AVFormatContext *s, int size)
61 FFMContext *ffm = s->priv_data;
62 int64_t pos, avail_size;
65 len = ffm->packet_end - ffm->packet_ptr;
68 pos = url_ftell(s->pb);
69 if (pos == ffm->write_index) {
70 /* exactly at the end of stream */
72 } else if (pos < ffm->write_index) {
73 avail_size = ffm->write_index - pos;
75 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
77 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
78 if (size <= avail_size)
84 /* first is true if we read the frame header */
85 static int ffm_read_data(AVFormatContext *s,
86 uint8_t *buf, int size, int header)
88 FFMContext *ffm = s->priv_data;
89 ByteIOContext *pb = s->pb;
90 int len, fill_size, size1, frame_offset;
95 len = ffm->packet_end - ffm->packet_ptr;
101 if (url_ftell(pb) == ffm->file_size)
102 url_fseek(pb, ffm->packet_size, SEEK_SET);
104 get_be16(pb); /* PACKET_ID */
105 fill_size = get_be16(pb);
106 ffm->dts = get_be64(pb);
107 frame_offset = get_be16(pb);
108 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
109 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
110 if (ffm->packet_end < ffm->packet || frame_offset < 0)
112 /* if first packet or resynchronization packet, we must
113 handle it specifically */
114 if (ffm->first_packet || (frame_offset & 0x8000)) {
116 /* This packet has no frame headers in it */
117 if (url_ftell(pb) >= ffm->packet_size * 3) {
118 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
121 /* This is bad, we cannot find a valid frame header */
124 ffm->first_packet = 0;
125 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
127 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
131 ffm->packet_ptr = ffm->packet;
135 memcpy(buf, ffm->packet_ptr, len);
137 ffm->packet_ptr += len;
146 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
147 by the write position inside this function */
148 static void ffm_seek1(AVFormatContext *s, int64_t pos1)
150 FFMContext *ffm = s->priv_data;
151 ByteIOContext *pb = s->pb;
154 pos = pos1 + ffm->write_index;
155 if (pos >= ffm->file_size)
156 pos -= (ffm->file_size - FFM_PACKET_SIZE);
158 av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
160 url_fseek(pb, pos, SEEK_SET);
163 static int64_t get_dts(AVFormatContext *s, int64_t pos)
165 ByteIOContext *pb = s->pb;
172 av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
177 static void adjust_write_index(AVFormatContext *s)
179 FFMContext *ffm = s->priv_data;
180 ByteIOContext *pb = s->pb;
182 //int64_t orig_write_index = ffm->write_index;
183 int64_t pos_min, pos_max;
185 int64_t ptr = url_ftell(pb);
189 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
191 pts_start = get_dts(s, pos_min);
193 pts = get_dts(s, pos_max);
195 if (pts - 100000 > pts_start)
198 ffm->write_index = FFM_PACKET_SIZE;
200 pts_start = get_dts(s, pos_min);
202 pts = get_dts(s, pos_max);
204 if (pts - 100000 <= pts_start) {
209 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
211 if (newpos == pos_min)
214 newpts = get_dts(s, newpos);
216 if (newpts - 100000 <= pts) {
223 ffm->write_index += pos_max;
226 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
227 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
230 url_fseek(pb, ptr, SEEK_SET);
234 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
236 FFMContext *ffm = s->priv_data;
238 ByteIOContext *pb = s->pb;
239 AVCodecContext *codec;
245 if (tag != MKTAG('F', 'F', 'M', '1'))
247 ffm->packet_size = get_be32(pb);
248 if (ffm->packet_size != FFM_PACKET_SIZE)
250 ffm->write_index = get_be64(pb);
251 /* get also filesize */
252 if (!url_is_streamed(pb)) {
253 ffm->file_size = url_fsize(pb);
254 adjust_write_index(s);
256 ffm->file_size = (UINT64_C(1) << 63) - 1;
259 nb_streams = get_be32(pb);
260 get_be32(pb); /* total bitrate */
261 /* read each stream */
262 for(i=0;i<nb_streams;i++) {
265 st = av_new_stream(s, 0);
270 av_set_pts_info(st, 64, 1, 1000000);
274 codec->codec_id = get_be32(pb);
275 codec->codec_type = get_byte(pb); /* codec_type */
276 codec->bit_rate = get_be32(pb);
277 st->quality = get_be32(pb);
278 codec->flags = get_be32(pb);
279 codec->flags2 = get_be32(pb);
280 codec->debug = get_be32(pb);
282 switch(codec->codec_type) {
283 case CODEC_TYPE_VIDEO:
284 codec->time_base.num = get_be32(pb);
285 codec->time_base.den = get_be32(pb);
286 codec->width = get_be16(pb);
287 codec->height = get_be16(pb);
288 codec->gop_size = get_be16(pb);
289 codec->pix_fmt = get_be32(pb);
290 codec->qmin = get_byte(pb);
291 codec->qmax = get_byte(pb);
292 codec->max_qdiff = get_byte(pb);
293 codec->qcompress = get_be16(pb) / 10000.0;
294 codec->qblur = get_be16(pb) / 10000.0;
295 codec->bit_rate_tolerance = get_be32(pb);
296 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
297 codec->rc_max_rate = get_be32(pb);
298 codec->rc_min_rate = get_be32(pb);
299 codec->rc_buffer_size = get_be32(pb);
300 codec->i_quant_factor = av_int2dbl(get_be64(pb));
301 codec->b_quant_factor = av_int2dbl(get_be64(pb));
302 codec->i_quant_offset = av_int2dbl(get_be64(pb));
303 codec->b_quant_offset = av_int2dbl(get_be64(pb));
304 codec->dct_algo = get_be32(pb);
305 codec->strict_std_compliance = get_be32(pb);
306 codec->max_b_frames = get_be32(pb);
307 codec->luma_elim_threshold = get_be32(pb);
308 codec->chroma_elim_threshold = get_be32(pb);
309 codec->mpeg_quant = get_be32(pb);
310 codec->intra_dc_precision = get_be32(pb);
311 codec->me_method = get_be32(pb);
312 codec->mb_decision = get_be32(pb);
313 codec->nsse_weight = get_be32(pb);
314 codec->frame_skip_cmp = get_be32(pb);
315 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
316 codec->codec_tag = get_be32(pb);
317 codec->thread_count = get_byte(pb);
319 case CODEC_TYPE_AUDIO:
320 codec->sample_rate = get_be32(pb);
321 codec->channels = get_le16(pb);
322 codec->frame_size = get_le16(pb);
327 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
328 codec->extradata_size = get_be32(pb);
329 codec->extradata = av_malloc(codec->extradata_size);
330 if (!codec->extradata)
331 return AVERROR(ENOMEM);
332 get_buffer(pb, codec->extradata, codec->extradata_size);
336 /* get until end of block reached */
337 while ((url_ftell(pb) % ffm->packet_size) != 0)
340 /* init packet demux */
341 ffm->packet_ptr = ffm->packet;
342 ffm->packet_end = ffm->packet;
343 ffm->frame_offset = 0;
345 ffm->read_state = READ_HEADER;
346 ffm->first_packet = 1;
349 for(i=0;i<s->nb_streams;i++) {
358 /* return < 0 if eof */
359 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
362 FFMContext *ffm = s->priv_data;
365 if (url_fsize(s->pb) == FFM_PACKET_SIZE)
368 switch(ffm->read_state) {
370 if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) {
371 return AVERROR(EAGAIN);
373 dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
374 url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
375 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
377 return AVERROR(EAGAIN);
378 if (ffm->header[1] & FLAG_DTS)
379 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
380 return AVERROR(EAGAIN);
382 av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
384 ffm->read_state = READ_DATA;
387 size = AV_RB24(ffm->header + 2);
388 if (!ffm_is_avail_data(s, size)) {
389 return AVERROR(EAGAIN);
392 duration = AV_RB24(ffm->header + 5);
394 av_new_packet(pkt, size);
395 pkt->stream_index = ffm->header[0];
396 if ((unsigned)pkt->stream_index >= s->nb_streams) {
397 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
399 ffm->read_state = READ_HEADER;
400 return AVERROR(EAGAIN);
402 pkt->pos = url_ftell(s->pb);
403 if (ffm->header[1] & FLAG_KEY_FRAME)
404 pkt->flags |= PKT_FLAG_KEY;
406 ffm->read_state = READ_HEADER;
407 if (ffm_read_data(s, pkt->data, size, 0) != size) {
408 /* bad case: desynchronized packet. we cancel all the packet loading */
410 return AVERROR(EAGAIN);
412 pkt->pts = AV_RB64(ffm->header+8);
413 if (ffm->header[1] & FLAG_DTS)
414 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
417 pkt->duration = duration;
423 /* seek to a given time in the file. The file read pointer is
424 positioned at or before pts. XXX: the following code is quite
426 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
428 FFMContext *ffm = s->priv_data;
429 int64_t pos_min, pos_max, pos;
430 int64_t pts_min, pts_max, pts;
434 av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
436 /* find the position using linear interpolation (better than
437 dichotomy in typical cases) */
439 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
440 while (pos_min <= pos_max) {
441 pts_min = get_dts(s, pos_min);
442 pts_max = get_dts(s, pos_max);
443 /* linear interpolation */
444 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
445 (double)(pts_max - pts_min);
446 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
449 else if (pos >= pos_max)
451 pts = get_dts(s, pos);
452 /* check if we are lucky */
453 if (pts == wanted_pts) {
455 } else if (pts > wanted_pts) {
456 pos_max = pos - FFM_PACKET_SIZE;
458 pos_min = pos + FFM_PACKET_SIZE;
461 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
463 pos -= FFM_PACKET_SIZE;
467 /* reset read state */
468 ffm->read_state = READ_HEADER;
469 ffm->packet_ptr = ffm->packet;
470 ffm->packet_end = ffm->packet;
471 ffm->first_packet = 1;
476 static int ffm_probe(AVProbeData *p)
479 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
481 return AVPROBE_SCORE_MAX + 1;
485 AVInputFormat ffm_demuxer = {
487 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),