/* * FFM (ffserver live feed) encoder and decoder * Copyright (c) 2001 Gerard Lantau. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "avformat.h" #include <unistd.h> /* The FFM file is made of blocks of fixed size */ #define FFM_HEADER_SIZE 14 #define PACKET_ID 0x666d /* each packet contains frames (which can span several packets */ #define FRAME_HEADER_SIZE 5 #define FLAG_KEY_FRAME 0x01 typedef struct FFMStream { INT64 pts; } FFMStream; enum { READ_HEADER, READ_DATA, }; typedef struct FFMContext { /* only reading mode */ offset_t write_index, file_size; int read_state; UINT8 header[FRAME_HEADER_SIZE]; /* read and write */ int first_packet; /* true if first packet, needed to set the discontinuity tag */ int packet_size; int frame_offset; INT64 pts; UINT8 *packet_ptr, *packet_end; UINT8 packet[1]; /* must be last */ } FFMContext; static void flush_packet(AVFormatContext *s) { FFMContext *ffm = s->priv_data; int fill_size, h; ByteIOContext *pb = &s->pb; fill_size = ffm->packet_end - ffm->packet_ptr; memset(ffm->packet_ptr, 0, fill_size); /* put header */ put_be16(pb, PACKET_ID); put_be16(pb, fill_size); put_be64(pb, ffm->pts); h = ffm->frame_offset; if (ffm->first_packet) h |= 0x8000; put_be16(pb, h); put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet); /* prepare next packet */ ffm->frame_offset = 0; /* no key frame */ ffm->pts = 0; /* no pts */ ffm->packet_ptr = ffm->packet; ffm->first_packet = 0; } /* 'first' is true if first data of a frame */ static void ffm_write_data(AVFormatContext *s, UINT8 *buf, int size, INT64 pts, int first) { FFMContext *ffm = s->priv_data; int len; if (first && ffm->frame_offset == 0) ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE; if (first && ffm->pts == 0) ffm->pts = pts; /* write as many packets as needed */ while (size > 0) { len = ffm->packet_end - ffm->packet_ptr; if (len > size) len = size; memcpy(ffm->packet_ptr, buf, len); ffm->packet_ptr += len; buf += len; size -= len; if (ffm->packet_ptr >= ffm->packet_end) { /* special case : no pts in packet : we leave the current one */ if (ffm->pts == 0) ffm->pts = pts; flush_packet(s); } } } static int ffm_write_header(AVFormatContext *s) { AVStream *st; FFMStream *fst; FFMContext *ffm; ByteIOContext *pb = &s->pb; AVCodecContext *codec; int bit_rate, i; ffm = av_mallocz(sizeof(FFMContext) + FFM_PACKET_SIZE); if (!ffm) return -1; s->priv_data = ffm; ffm->packet_size = FFM_PACKET_SIZE; /* header */ put_tag(pb, "FFM1"); put_be32(pb, ffm->packet_size); /* XXX: store write position in other file ? */ put_be64(pb, ffm->packet_size); /* current write position */ put_be32(pb, s->nb_streams); bit_rate = 0; for(i=0;i<s->nb_streams;i++) { st = s->streams[i]; bit_rate += st->codec.bit_rate; } put_be32(pb, bit_rate); /* list of streams */ for(i=0;i<s->nb_streams;i++) { st = s->streams[i]; fst = av_mallocz(sizeof(FFMStream) + ffm->packet_size); if (!fst) goto fail; st->priv_data = fst; codec = &st->codec; /* generic info */ put_be32(pb, codec->codec_id); put_byte(pb, codec->codec_type); put_be32(pb, codec->bit_rate); /* specific info */ switch(codec->codec_type) { case CODEC_TYPE_VIDEO: put_be32(pb, (codec->frame_rate * 1000) / FRAME_RATE_BASE); put_be16(pb, codec->width); put_be16(pb, codec->height); break; case CODEC_TYPE_AUDIO: put_be32(pb, codec->sample_rate); put_le16(pb, codec->channels); break; } /* hack to have real time */ fst->pts = gettime(); } /* flush until end of block reached */ while ((url_ftell(pb) % ffm->packet_size) != 0) put_byte(pb, 0); put_flush_packet(pb); /* init packet mux */ ffm->packet_ptr = ffm->packet; ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE; ffm->frame_offset = 0; ffm->pts = 0; ffm->first_packet = 1; return 0; fail: for(i=0;i<s->nb_streams;i++) { st = s->streams[i]; fst = st->priv_data; if (fst) free(fst); } free(ffm); return -1; } static int ffm_write_packet(AVFormatContext *s, int stream_index, UINT8 *buf, int size) { AVStream *st = s->streams[stream_index]; FFMStream *fst = st->priv_data; INT64 pts; UINT8 header[FRAME_HEADER_SIZE]; pts = fst->pts; /* packet size & key_frame */ header[0] = stream_index; header[1] = 0; if (st->codec.key_frame) header[1] |= FLAG_KEY_FRAME; header[2] = (size >> 16) & 0xff; header[3] = (size >> 8) & 0xff; header[4] = size & 0xff; ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1); ffm_write_data(s, buf, size, pts, 0); if (st->codec.codec_type == CODEC_TYPE_AUDIO) { fst->pts += (INT64)((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0); } else { fst->pts += (INT64)(1000000.0 * FRAME_RATE_BASE / (float)st->codec.frame_rate); } return 0; } static int ffm_write_trailer(AVFormatContext *s) { ByteIOContext *pb = &s->pb; FFMContext *ffm = s->priv_data; int i; /* flush packets */ if (ffm->packet_ptr > ffm->packet) flush_packet(s); put_flush_packet(pb); for(i=0;i<s->nb_streams;i++) free(s->streams[i]->priv_data); free(ffm); return 0; } /* ffm demux */ static int ffm_is_avail_data(AVFormatContext *s, int size) { FFMContext *ffm = s->priv_data; offset_t pos, avail_size; int len; len = ffm->packet_end - ffm->packet_ptr; if (size <= len) return 1; pos = url_ftell(&s->pb); if (pos == ffm->write_index) { /* exactly at the end of stream */ return 0; } 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 0; } /* first is true if we read the frame header */ static int ffm_read_data(AVFormatContext *s, UINT8 *buf, int size, int first) { FFMContext *ffm = s->priv_data; ByteIOContext *pb = &s->pb; int len, fill_size, size1, frame_offset; size1 = size; while (size > 0) { redo: len = ffm->packet_end - ffm->packet_ptr; if (len > size) len = size; if (len == 0) { if (url_ftell(pb) == ffm->file_size) url_fseek(pb, ffm->packet_size, SEEK_SET); get_be16(pb); /* PACKET_ID */ fill_size = get_be16(pb); ffm->pts = get_be64(pb); frame_offset = get_be16(pb); get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE); ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size); /* if first packet or resynchronization packet, we must handle it specifically */ if (ffm->first_packet || (frame_offset & 0x8000)) { ffm->first_packet = 0; ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE; if (!first) break; } else { ffm->packet_ptr = ffm->packet; } goto redo; } memcpy(buf, ffm->packet_ptr, len); buf += len; ffm->packet_ptr += len; size -= len; first = 0; } return size1 - size; } static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap) { AVStream *st; FFMStream *fst; FFMContext *ffm; ByteIOContext *pb = &s->pb; AVCodecContext *codec; int i; UINT32 tag; ffm = av_mallocz(sizeof(FFMContext) + FFM_PACKET_SIZE); if (!ffm) return -1; s->priv_data = ffm; /* header */ tag = get_le32(pb); if (tag != MKTAG('F', 'F', 'M', '1')) goto fail; ffm->packet_size = get_be32(pb); if (ffm->packet_size != FFM_PACKET_SIZE) goto fail; ffm->write_index = get_be64(pb); /* get also filesize */ if (!url_is_streamed(pb)) { ffm->file_size = url_filesize(url_fileno(pb)); } else { ffm->file_size = (UINT64_C(1) << 63) - 1; } s->nb_streams = get_be32(pb); get_be32(pb); /* total bitrate */ /* read each stream */ for(i=0;i<s->nb_streams;i++) { st = av_mallocz(sizeof(AVStream)); if (!st) goto fail; s->streams[i] = st; fst = av_mallocz(sizeof(FFMStream) + ffm->packet_size); if (!fst) goto fail; st->priv_data = fst; codec = &st->codec; /* generic info */ st->codec.codec_id = get_be32(pb); st->codec.codec_type = get_byte(pb); /* codec_type */ codec->bit_rate = get_be32(pb); /* specific info */ switch(codec->codec_type) { case CODEC_TYPE_VIDEO: codec->frame_rate = ((INT64)get_be32(pb) * FRAME_RATE_BASE) / 1000; codec->width = get_be16(pb); codec->height = get_be16(pb); break; case CODEC_TYPE_AUDIO: codec->sample_rate = get_be32(pb); codec->channels = get_le16(pb); break; } } /* get until end of block reached */ while ((url_ftell(pb) % ffm->packet_size) != 0) get_byte(pb); /* init packet demux */ ffm->packet_ptr = ffm->packet; ffm->packet_end = ffm->packet; ffm->frame_offset = 0; ffm->pts = 0; ffm->read_state = READ_HEADER; ffm->first_packet = 1; return 0; fail: for(i=0;i<s->nb_streams;i++) { st = s->streams[i]; if (st) { fst = st->priv_data; if (fst) free(fst); free(st); } } if (ffm) free(ffm); return -1; } /* return < 0 if eof */ static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt) { int size; FFMContext *ffm = s->priv_data; switch(ffm->read_state) { case READ_HEADER: if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) return -EAGAIN; #if 0 printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n", url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size); #endif if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != FRAME_HEADER_SIZE) return -EAGAIN; #if 0 { int i; for(i=0;i<FRAME_HEADER_SIZE;i++) printf("%02x ", ffm->header[i]); printf("\n"); } #endif ffm->read_state = READ_DATA; /* fall thru */ case READ_DATA: size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4]; if (!ffm_is_avail_data(s, size)) { return -EAGAIN; } av_new_packet(pkt, size); pkt->stream_index = ffm->header[0]; if (ffm->header[1] & FLAG_KEY_FRAME) pkt->flags |= 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 -EAGAIN; } break; } return 0; } //#define DEBUG_SEEK /* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated by the write position inside this function */ static void ffm_seek1(AVFormatContext *s, offset_t pos1) { FFMContext *ffm = s->priv_data; ByteIOContext *pb = &s->pb; offset_t pos; pos = pos1 + ffm->write_index; if (pos >= ffm->file_size) pos -= (ffm->file_size - FFM_PACKET_SIZE); #ifdef DEBUG_SEEK printf("seek to %Lx -> %Lx\n", pos1, pos); #endif url_fseek(pb, pos, SEEK_SET); } static INT64 get_pts(AVFormatContext *s, offset_t pos) { ByteIOContext *pb = &s->pb; INT64 pts; ffm_seek1(s, pos); url_fskip(pb, 4); pts = get_be64(pb); #ifdef DEBUG_SEEK printf("pts=%0.6f\n", pts / 1000000.0); #endif return pts; } /* seek to a given time in the file. The file read pointer is positionned at or before pts. XXX: the following code is quite approximative */ static int ffm_seek(AVFormatContext *s, INT64 wanted_pts) { FFMContext *ffm = s->priv_data; offset_t pos_min, pos_max, pos; INT64 pts_min, pts_max, pts; double pos1; #ifdef DEBUG_SEEK printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0); #endif /* find the position using linear interpolation (better than dichotomy in typical cases) */ pos_min = 0; pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE; while (pos_min <= pos_max) { pts_min = get_pts(s, pos_min); pts_max = get_pts(s, pos_max); /* linear interpolation */ pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) / (double)(pts_max - pts_min); pos = (((INT64)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE; if (pos <= pos_min) pos = pos_min; else if (pos >= pos_max) pos = pos_max; pts = get_pts(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 = pos_min; if (pos > 0) pos -= FFM_PACKET_SIZE; found: ffm_seek1(s, pos); return 0; } offset_t ffm_read_write_index(int fd) { UINT8 buf[8]; offset_t pos; int i; lseek(fd, 8, SEEK_SET); read(fd, buf, 8); pos = 0; for(i=0;i<8;i++) pos |= buf[i] << (56 - i * 8); return pos; } void ffm_write_write_index(int fd, offset_t pos) { UINT8 buf[8]; int i; for(i=0;i<8;i++) buf[i] = (pos >> (56 - i * 8)) & 0xff; lseek(fd, 8, SEEK_SET); write(fd, buf, 8); } void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size) { FFMContext *ffm = s->priv_data; ffm->write_index = pos; ffm->file_size = file_size; } static int ffm_read_close(AVFormatContext *s) { AVStream *st; int i; for(i=0;i<s->nb_streams;i++) { st = s->streams[i]; free(st->priv_data); } free(s->priv_data); return 0; } AVFormat ffm_format = { "ffm", "ffm format", "", "ffm", /* not really used */ CODEC_ID_MP2, CODEC_ID_MPEG1VIDEO, ffm_write_header, ffm_write_packet, ffm_write_trailer, ffm_read_header, ffm_read_packet, ffm_read_close, ffm_seek, };