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 (!ffm->write_index) {
70 if (pos == ffm->file_size)
72 avail_size = ffm->file_size - pos;
74 if (pos == ffm->write_index) {
75 /* exactly at the end of stream */
76 return AVERROR(EAGAIN);
77 } else if (pos < ffm->write_index) {
78 avail_size = ffm->write_index - pos;
80 avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
83 avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
84 if (size <= avail_size)
87 return AVERROR(EAGAIN);
90 /* first is true if we read the frame header */
91 static int ffm_read_data(AVFormatContext *s,
92 uint8_t *buf, int size, int header)
94 FFMContext *ffm = s->priv_data;
95 ByteIOContext *pb = s->pb;
96 int len, fill_size, size1, frame_offset;
101 len = ffm->packet_end - ffm->packet_ptr;
107 if (url_ftell(pb) == ffm->file_size)
108 url_fseek(pb, ffm->packet_size, SEEK_SET);
110 get_be16(pb); /* PACKET_ID */
111 fill_size = get_be16(pb);
112 ffm->dts = get_be64(pb);
113 frame_offset = get_be16(pb);
114 get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
115 ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
116 if (ffm->packet_end < ffm->packet || frame_offset < 0)
118 /* if first packet or resynchronization packet, we must
119 handle it specifically */
120 if (ffm->first_packet || (frame_offset & 0x8000)) {
122 /* This packet has no frame headers in it */
123 if (url_ftell(pb) >= ffm->packet_size * 3) {
124 url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
127 /* This is bad, we cannot find a valid frame header */
130 ffm->first_packet = 0;
131 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
133 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
137 ffm->packet_ptr = ffm->packet;
141 memcpy(buf, ffm->packet_ptr, len);
143 ffm->packet_ptr += len;
152 /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
153 by the write position inside this function */
154 static void ffm_seek1(AVFormatContext *s, int64_t pos1)
156 FFMContext *ffm = s->priv_data;
157 ByteIOContext *pb = s->pb;
160 pos = pos1 + ffm->write_index;
161 if (pos >= ffm->file_size)
162 pos -= (ffm->file_size - FFM_PACKET_SIZE);
164 av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
166 url_fseek(pb, pos, SEEK_SET);
169 static int64_t get_dts(AVFormatContext *s, int64_t pos)
171 ByteIOContext *pb = s->pb;
178 av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
183 static void adjust_write_index(AVFormatContext *s)
185 FFMContext *ffm = s->priv_data;
186 ByteIOContext *pb = s->pb;
188 //int64_t orig_write_index = ffm->write_index;
189 int64_t pos_min, pos_max;
191 int64_t ptr = url_ftell(pb);
195 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
197 pts_start = get_dts(s, pos_min);
199 pts = get_dts(s, pos_max);
201 if (pts - 100000 > pts_start)
204 ffm->write_index = FFM_PACKET_SIZE;
206 pts_start = get_dts(s, pos_min);
208 pts = get_dts(s, pos_max);
210 if (pts - 100000 <= pts_start) {
215 newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
217 if (newpos == pos_min)
220 newpts = get_dts(s, newpos);
222 if (newpts - 100000 <= pts) {
229 ffm->write_index += pos_max;
232 //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
233 //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
236 url_fseek(pb, ptr, SEEK_SET);
240 static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
242 FFMContext *ffm = s->priv_data;
244 ByteIOContext *pb = s->pb;
245 AVCodecContext *codec;
251 if (tag != MKTAG('F', 'F', 'M', '1'))
253 ffm->packet_size = get_be32(pb);
254 if (ffm->packet_size != FFM_PACKET_SIZE)
256 ffm->write_index = get_be64(pb);
257 /* get also filesize */
258 if (!url_is_streamed(pb)) {
259 ffm->file_size = url_fsize(pb);
260 if (ffm->write_index)
261 adjust_write_index(s);
263 ffm->file_size = (UINT64_C(1) << 63) - 1;
266 nb_streams = get_be32(pb);
267 get_be32(pb); /* total bitrate */
268 /* read each stream */
269 for(i=0;i<nb_streams;i++) {
272 st = av_new_stream(s, 0);
277 av_set_pts_info(st, 64, 1, 1000000);
281 codec->codec_id = get_be32(pb);
282 codec->codec_type = get_byte(pb); /* codec_type */
283 codec->bit_rate = get_be32(pb);
284 st->quality = get_be32(pb);
285 codec->flags = get_be32(pb);
286 codec->flags2 = get_be32(pb);
287 codec->debug = get_be32(pb);
289 switch(codec->codec_type) {
290 case CODEC_TYPE_VIDEO:
291 codec->time_base.num = get_be32(pb);
292 codec->time_base.den = get_be32(pb);
293 codec->width = get_be16(pb);
294 codec->height = get_be16(pb);
295 codec->gop_size = get_be16(pb);
296 codec->pix_fmt = get_be32(pb);
297 codec->qmin = get_byte(pb);
298 codec->qmax = get_byte(pb);
299 codec->max_qdiff = get_byte(pb);
300 codec->qcompress = get_be16(pb) / 10000.0;
301 codec->qblur = get_be16(pb) / 10000.0;
302 codec->bit_rate_tolerance = get_be32(pb);
303 codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
304 codec->rc_max_rate = get_be32(pb);
305 codec->rc_min_rate = get_be32(pb);
306 codec->rc_buffer_size = get_be32(pb);
307 codec->i_quant_factor = av_int2dbl(get_be64(pb));
308 codec->b_quant_factor = av_int2dbl(get_be64(pb));
309 codec->i_quant_offset = av_int2dbl(get_be64(pb));
310 codec->b_quant_offset = av_int2dbl(get_be64(pb));
311 codec->dct_algo = get_be32(pb);
312 codec->strict_std_compliance = get_be32(pb);
313 codec->max_b_frames = get_be32(pb);
314 codec->luma_elim_threshold = get_be32(pb);
315 codec->chroma_elim_threshold = get_be32(pb);
316 codec->mpeg_quant = get_be32(pb);
317 codec->intra_dc_precision = get_be32(pb);
318 codec->me_method = get_be32(pb);
319 codec->mb_decision = get_be32(pb);
320 codec->nsse_weight = get_be32(pb);
321 codec->frame_skip_cmp = get_be32(pb);
322 codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
323 codec->codec_tag = get_be32(pb);
324 codec->thread_count = get_byte(pb);
326 case CODEC_TYPE_AUDIO:
327 codec->sample_rate = get_be32(pb);
328 codec->channels = get_le16(pb);
329 codec->frame_size = get_le16(pb);
334 if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
335 codec->extradata_size = get_be32(pb);
336 codec->extradata = av_malloc(codec->extradata_size);
337 if (!codec->extradata)
338 return AVERROR(ENOMEM);
339 get_buffer(pb, codec->extradata, codec->extradata_size);
343 /* get until end of block reached */
344 while ((url_ftell(pb) % ffm->packet_size) != 0)
347 /* init packet demux */
348 ffm->packet_ptr = ffm->packet;
349 ffm->packet_end = ffm->packet;
350 ffm->frame_offset = 0;
352 ffm->read_state = READ_HEADER;
353 ffm->first_packet = 1;
356 for(i=0;i<s->nb_streams;i++) {
365 /* return < 0 if eof */
366 static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
369 FFMContext *ffm = s->priv_data;
372 switch(ffm->read_state) {
374 if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
377 dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
378 url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
379 if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
382 if (ffm->header[1] & FLAG_DTS)
383 if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
386 av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
388 ffm->read_state = READ_DATA;
391 size = AV_RB24(ffm->header + 2);
392 if ((ret = ffm_is_avail_data(s, size)) < 0)
395 duration = AV_RB24(ffm->header + 5);
397 av_new_packet(pkt, size);
398 pkt->stream_index = ffm->header[0];
399 if ((unsigned)pkt->stream_index >= s->nb_streams) {
400 av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
402 ffm->read_state = READ_HEADER;
405 pkt->pos = url_ftell(s->pb);
406 if (ffm->header[1] & FLAG_KEY_FRAME)
407 pkt->flags |= PKT_FLAG_KEY;
409 ffm->read_state = READ_HEADER;
410 if (ffm_read_data(s, pkt->data, size, 0) != size) {
411 /* bad case: desynchronized packet. we cancel all the packet loading */
415 pkt->pts = AV_RB64(ffm->header+8);
416 if (ffm->header[1] & FLAG_DTS)
417 pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
420 pkt->duration = duration;
426 /* seek to a given time in the file. The file read pointer is
427 positioned at or before pts. XXX: the following code is quite
429 static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
431 FFMContext *ffm = s->priv_data;
432 int64_t pos_min, pos_max, pos;
433 int64_t pts_min, pts_max, pts;
437 av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
439 /* find the position using linear interpolation (better than
440 dichotomy in typical cases) */
442 pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
443 while (pos_min <= pos_max) {
444 pts_min = get_dts(s, pos_min);
445 pts_max = get_dts(s, pos_max);
446 /* linear interpolation */
447 pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
448 (double)(pts_max - pts_min);
449 pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
452 else if (pos >= pos_max)
454 pts = get_dts(s, pos);
455 /* check if we are lucky */
456 if (pts == wanted_pts) {
458 } else if (pts > wanted_pts) {
459 pos_max = pos - FFM_PACKET_SIZE;
461 pos_min = pos + FFM_PACKET_SIZE;
464 pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
466 pos -= FFM_PACKET_SIZE;
470 /* reset read state */
471 ffm->read_state = READ_HEADER;
472 ffm->packet_ptr = ffm->packet;
473 ffm->packet_end = ffm->packet;
474 ffm->first_packet = 1;
479 static int ffm_probe(AVProbeData *p)
482 p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
484 return AVPROBE_SCORE_MAX + 1;
488 AVInputFormat ffm_demuxer = {
490 NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),