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