/* * FFM (ffserver live feed) demuxer * Copyright (c) 2001 Fabrice Bellard * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/intreadwrite.h" #include "avformat.h" #include "ffm.h" #if CONFIG_FFSERVER #include <unistd.h> int64_t ffm_read_write_index(int fd) { uint8_t buf[8]; lseek(fd, 8, SEEK_SET); if (read(fd, buf, 8) != 8) return AVERROR(EIO); return AV_RB64(buf); } int ffm_write_write_index(int fd, int64_t pos) { uint8_t buf[8]; int i; for(i=0;i<8;i++) buf[i] = (pos >> (56 - i * 8)) & 0xff; lseek(fd, 8, SEEK_SET); if (write(fd, buf, 8) != 8) return AVERROR(EIO); return 8; } void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size) { FFMContext *ffm = s->priv_data; ffm->write_index = pos; ffm->file_size = file_size; } #endif // CONFIG_FFSERVER static int ffm_is_avail_data(AVFormatContext *s, int size) { FFMContext *ffm = s->priv_data; int64_t pos, avail_size; int len; len = ffm->packet_end - ffm->packet_ptr; if (size <= len) return 1; pos = avio_tell(s->pb); if (!ffm->write_index) { if (pos == ffm->file_size) return AVERROR_EOF; avail_size = ffm->file_size - pos; } else { if (pos == ffm->write_index) { /* exactly at the end of stream */ return AVERROR(EAGAIN); } else if (pos < ffm->write_index) { avail_size = ffm->write_index - pos; } else { avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE); } } avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len; if (size <= avail_size) return 1; else return AVERROR(EAGAIN); } static int ffm_resync(AVFormatContext *s, int state) { av_log(s, AV_LOG_ERROR, "resyncing\n"); while (state != PACKET_ID) { if (s->pb->eof_reached) { av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n"); return -1; } state = (state << 8) | avio_r8(s->pb); } return 0; } /* first is true if we read the frame header */ static int ffm_read_data(AVFormatContext *s, uint8_t *buf, int size, int header) { FFMContext *ffm = s->priv_data; AVIOContext *pb = s->pb; int len, fill_size, size1, frame_offset, id; size1 = size; while (size > 0) { redo: len = ffm->packet_end - ffm->packet_ptr; if (len < 0) return -1; if (len > size) len = size; if (len == 0) { if (avio_tell(pb) == ffm->file_size) avio_seek(pb, ffm->packet_size, SEEK_SET); retry_read: id = avio_rb16(pb); /* PACKET_ID */ if (id != PACKET_ID) if (ffm_resync(s, id) < 0) return -1; fill_size = avio_rb16(pb); ffm->dts = avio_rb64(pb); frame_offset = avio_rb16(pb); avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE); ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size); if (ffm->packet_end < ffm->packet || frame_offset < 0) return -1; /* if first packet or resynchronization packet, we must handle it specifically */ if (ffm->first_packet || (frame_offset & 0x8000)) { if (!frame_offset) { /* This packet has no frame headers in it */ if (avio_tell(pb) >= ffm->packet_size * 3) { avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR); goto retry_read; } /* This is bad, we cannot find a valid frame header */ return 0; } ffm->first_packet = 0; if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE) return -1; ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE; if (!header) break; } else { ffm->packet_ptr = ffm->packet; } goto redo; } memcpy(buf, ffm->packet_ptr, len); buf += len; ffm->packet_ptr += len; size -= len; header = 0; } return size1 - size; } /* ensure that acutal seeking happens between FFM_PACKET_SIZE and file_size - FFM_PACKET_SIZE */ static void ffm_seek1(AVFormatContext *s, int64_t pos1) { FFMContext *ffm = s->priv_data; AVIOContext *pb = s->pb; int64_t pos; pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE); pos = FFMAX(pos, FFM_PACKET_SIZE); av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos); avio_seek(pb, pos, SEEK_SET); } static int64_t get_dts(AVFormatContext *s, int64_t pos) { AVIOContext *pb = s->pb; int64_t dts; ffm_seek1(s, pos); avio_skip(pb, 4); dts = avio_rb64(pb); av_dlog(s, "dts=%0.6f\n", dts / 1000000.0); return dts; } static void adjust_write_index(AVFormatContext *s) { FFMContext *ffm = s->priv_data; AVIOContext *pb = s->pb; int64_t pts; //int64_t orig_write_index = ffm->write_index; int64_t pos_min, pos_max; int64_t pts_start; int64_t ptr = avio_tell(pb); pos_min = 0; pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE; pts_start = get_dts(s, pos_min); pts = get_dts(s, pos_max); if (pts - 100000 > pts_start) goto end; ffm->write_index = FFM_PACKET_SIZE; pts_start = get_dts(s, pos_min); pts = get_dts(s, pos_max); if (pts - 100000 <= pts_start) { while (1) { int64_t newpos; int64_t newpts; newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE; if (newpos == pos_min) break; newpts = get_dts(s, newpos); if (newpts - 100000 <= pts) { pos_max = newpos; pts = newpts; } else { pos_min = newpos; } } ffm->write_index += pos_max; } //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.); //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. ); end: avio_seek(pb, ptr, SEEK_SET); } static int ffm_close(AVFormatContext *s) { int i; for (i = 0; i < s->nb_streams; i++) av_freep(&s->streams[i]->codec->rc_eq); return 0; } static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap) { FFMContext *ffm = s->priv_data; AVStream *st; AVIOContext *pb = s->pb; AVCodecContext *codec; int i, nb_streams; uint32_t tag; /* header */ tag = avio_rl32(pb); if (tag != MKTAG('F', 'F', 'M', '1')) goto fail; ffm->packet_size = avio_rb32(pb); if (ffm->packet_size != FFM_PACKET_SIZE) goto fail; ffm->write_index = avio_rb64(pb); /* get also filesize */ if (pb->seekable) { ffm->file_size = avio_size(pb); if (ffm->write_index) adjust_write_index(s); } else { ffm->file_size = (UINT64_C(1) << 63) - 1; } nb_streams = avio_rb32(pb); avio_rb32(pb); /* total bitrate */ /* read each stream */ for(i=0;i<nb_streams;i++) { char rc_eq_buf[128]; st = av_new_stream(s, 0); if (!st) goto fail; av_set_pts_info(st, 64, 1, 1000000); codec = st->codec; /* generic info */ codec->codec_id = avio_rb32(pb); codec->codec_type = avio_r8(pb); /* codec_type */ codec->bit_rate = avio_rb32(pb); st->quality = avio_rb32(pb); codec->flags = avio_rb32(pb); codec->flags2 = avio_rb32(pb); codec->debug = avio_rb32(pb); /* specific info */ switch(codec->codec_type) { case AVMEDIA_TYPE_VIDEO: codec->time_base.num = avio_rb32(pb); codec->time_base.den = avio_rb32(pb); codec->width = avio_rb16(pb); codec->height = avio_rb16(pb); codec->gop_size = avio_rb16(pb); codec->pix_fmt = avio_rb32(pb); codec->qmin = avio_r8(pb); codec->qmax = avio_r8(pb); codec->max_qdiff = avio_r8(pb); codec->qcompress = avio_rb16(pb) / 10000.0; codec->qblur = avio_rb16(pb) / 10000.0; codec->bit_rate_tolerance = avio_rb32(pb); avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf)); codec->rc_eq = av_strdup(rc_eq_buf); codec->rc_max_rate = avio_rb32(pb); codec->rc_min_rate = avio_rb32(pb); codec->rc_buffer_size = avio_rb32(pb); codec->i_quant_factor = av_int2dbl(avio_rb64(pb)); codec->b_quant_factor = av_int2dbl(avio_rb64(pb)); codec->i_quant_offset = av_int2dbl(avio_rb64(pb)); codec->b_quant_offset = av_int2dbl(avio_rb64(pb)); codec->dct_algo = avio_rb32(pb); codec->strict_std_compliance = avio_rb32(pb); codec->max_b_frames = avio_rb32(pb); codec->luma_elim_threshold = avio_rb32(pb); codec->chroma_elim_threshold = avio_rb32(pb); codec->mpeg_quant = avio_rb32(pb); codec->intra_dc_precision = avio_rb32(pb); codec->me_method = avio_rb32(pb); codec->mb_decision = avio_rb32(pb); codec->nsse_weight = avio_rb32(pb); codec->frame_skip_cmp = avio_rb32(pb); codec->rc_buffer_aggressivity = av_int2dbl(avio_rb64(pb)); codec->codec_tag = avio_rb32(pb); codec->thread_count = avio_r8(pb); codec->coder_type = avio_rb32(pb); codec->me_cmp = avio_rb32(pb); codec->partitions = avio_rb32(pb); codec->me_subpel_quality = avio_rb32(pb); codec->me_range = avio_rb32(pb); codec->keyint_min = avio_rb32(pb); codec->scenechange_threshold = avio_rb32(pb); codec->b_frame_strategy = avio_rb32(pb); codec->qcompress = av_int2dbl(avio_rb64(pb)); codec->qblur = av_int2dbl(avio_rb64(pb)); codec->max_qdiff = avio_rb32(pb); codec->refs = avio_rb32(pb); codec->directpred = avio_rb32(pb); break; case AVMEDIA_TYPE_AUDIO: codec->sample_rate = avio_rb32(pb); codec->channels = avio_rl16(pb); codec->frame_size = avio_rl16(pb); codec->sample_fmt = (int16_t) avio_rl16(pb); break; default: goto fail; } if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) { codec->extradata_size = avio_rb32(pb); codec->extradata = av_malloc(codec->extradata_size); if (!codec->extradata) return AVERROR(ENOMEM); avio_read(pb, codec->extradata, codec->extradata_size); } } /* get until end of block reached */ while ((avio_tell(pb) % ffm->packet_size) != 0) avio_r8(pb); /* init packet demux */ ffm->packet_ptr = ffm->packet; ffm->packet_end = ffm->packet; ffm->frame_offset = 0; ffm->dts = 0; ffm->read_state = READ_HEADER; ffm->first_packet = 1; return 0; fail: ffm_close(s); return -1; } /* return < 0 if eof */ static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt) { int size; FFMContext *ffm = s->priv_data; int duration, ret; switch(ffm->read_state) { case READ_HEADER: if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0) return ret; av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n", avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size); if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != FRAME_HEADER_SIZE) return -1; if (ffm->header[1] & FLAG_DTS) if (ffm_read_data(s, ffm->header+16, 4, 1) != 4) return -1; ffm->read_state = READ_DATA; /* fall thru */ case READ_DATA: size = AV_RB24(ffm->header + 2); if ((ret = ffm_is_avail_data(s, size)) < 0) return ret; duration = AV_RB24(ffm->header + 5); av_new_packet(pkt, size); pkt->stream_index = ffm->header[0]; if ((unsigned)pkt->stream_index >= s->nb_streams) { av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index); av_free_packet(pkt); ffm->read_state = READ_HEADER; return -1; } pkt->pos = avio_tell(s->pb); if (ffm->header[1] & FLAG_KEY_FRAME) pkt->flags |= AV_PKT_FLAG_KEY; ffm->read_state = READ_HEADER; if (ffm_read_data(s, pkt->data, size, 0) != size) { /* bad case: desynchronized packet. we cancel all the packet loading */ av_free_packet(pkt); return -1; } pkt->pts = AV_RB64(ffm->header+8); if (ffm->header[1] & FLAG_DTS) pkt->dts = pkt->pts - AV_RB32(ffm->header+16); else pkt->dts = pkt->pts; pkt->duration = duration; break; } return 0; } /* seek to a given time in the file. The file read pointer is positioned at or before pts. XXX: the following code is quite approximative */ static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags) { FFMContext *ffm = s->priv_data; int64_t pos_min, pos_max, pos; int64_t pts_min, pts_max, pts; double pos1; av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0); /* find the position using linear interpolation (better than dichotomy in typical cases) */ pos_min = FFM_PACKET_SIZE; pos_max = ffm->file_size - FFM_PACKET_SIZE; while (pos_min <= pos_max) { pts_min = get_dts(s, pos_min); pts_max = get_dts(s, pos_max); /* linear interpolation */ pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) / (double)(pts_max - pts_min); pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE; if (pos <= pos_min) pos = pos_min; else if (pos >= pos_max) pos = pos_max; pts = get_dts(s, pos); /* check if we are lucky */ if (pts == wanted_pts) { goto found; } else if (pts > wanted_pts) { pos_max = pos - FFM_PACKET_SIZE; } else { pos_min = pos + FFM_PACKET_SIZE; } } pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max; found: ffm_seek1(s, pos); /* reset read state */ ffm->read_state = READ_HEADER; ffm->packet_ptr = ffm->packet; ffm->packet_end = ffm->packet; ffm->first_packet = 1; return 0; } static int ffm_probe(AVProbeData *p) { if ( p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' && p->buf[3] == '1') return AVPROBE_SCORE_MAX + 1; return 0; } AVInputFormat ff_ffm_demuxer = { "ffm", NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"), sizeof(FFMContext), ffm_probe, ffm_read_header, ffm_read_packet, ffm_close, ffm_seek, };