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ffmpeg/libavformat/ffm.c
Philip Gladstone 91628427ec Add more resilience in reading ffm files. In particular, don't assume 
that the write pointer is correct. This can happen in certain failure
modes.

Originally committed as revision 2524 to svn://svn.ffmpeg.org/ffmpeg/trunk
2003-11-19 02:34:40 +00:00

758 lines
21 KiB
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/*
* FFM (ffserver live feed) encoder and decoder
* Copyright (c) 2001 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 8
#define FLAG_KEY_FRAME 0x01
typedef struct FFMStream {
int64_t pts;
} FFMStream;
enum {
READ_HEADER,
READ_DATA,
};
typedef struct FFMContext {
/* only reading mode */
offset_t write_index, file_size;
int read_state;
uint8_t 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_t pts;
uint8_t *packet_ptr, *packet_end;
uint8_t packet[FFM_PACKET_SIZE];
} FFMContext;
static int64_t get_pts(AVFormatContext *s, offset_t pos);
/* disable pts hack for testing */
int ffm_nopts = 0;
#ifdef CONFIG_ENCODERS
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);
if (url_ftell(pb) % ffm->packet_size)
av_abort();
/* 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,
const uint8_t *buf, int size,
int64_t 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)
{
FFMContext *ffm = s->priv_data;
AVStream *st;
FFMStream *fst;
ByteIOContext *pb = &s->pb;
AVCodecContext *codec;
int bit_rate, i;
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));
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);
put_be32(pb, st->quality);
put_be32(pb, codec->flags);
/* specific info */
switch(codec->codec_type) {
case CODEC_TYPE_VIDEO:
put_be32(pb, codec->frame_rate_base);
put_be32(pb, codec->frame_rate);
put_be16(pb, codec->width);
put_be16(pb, codec->height);
put_be16(pb, codec->gop_size);
put_byte(pb, codec->qmin);
put_byte(pb, codec->qmax);
put_byte(pb, codec->max_qdiff);
put_be16(pb, (int) (codec->qcompress * 10000.0));
put_be16(pb, (int) (codec->qblur * 10000.0));
put_be32(pb, codec->bit_rate_tolerance);
put_strz(pb, codec->rc_eq);
put_be32(pb, codec->rc_max_rate);
put_be32(pb, codec->rc_min_rate);
put_be32(pb, codec->rc_buffer_size);
put_be64_double(pb, codec->i_quant_factor);
put_be64_double(pb, codec->b_quant_factor);
put_be64_double(pb, codec->i_quant_offset);
put_be64_double(pb, codec->b_quant_offset);
put_be32(pb, codec->dct_algo);
break;
case CODEC_TYPE_AUDIO:
put_be32(pb, codec->sample_rate);
put_le16(pb, codec->channels);
put_le16(pb, codec->frame_size);
break;
default:
av_abort();
}
/* hack to have real time */
if (ffm_nopts)
fst->pts = 0;
else
fst->pts = av_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;
if (ffm->packet_end < ffm->packet)
av_abort();
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];
av_freep(&st->priv_data);
}
return -1;
}
static int ffm_write_packet(AVFormatContext *s, int stream_index,
const uint8_t *buf, int size, int64_t force_pts)
{
AVStream *st = s->streams[stream_index];
FFMStream *fst = st->priv_data;
int64_t pts;
uint8_t header[FRAME_HEADER_SIZE];
int duration;
if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
} else {
duration = (1000000.0 * st->codec.frame_rate_base / (float)st->codec.frame_rate);
}
pts = fst->pts;
/* packet size & key_frame */
header[0] = stream_index;
header[1] = 0;
if (st->codec.coded_frame->key_frame) //if st->codec.coded_frame==NULL then there is a bug somewhere else
header[1] |= FLAG_KEY_FRAME;
header[2] = (size >> 16) & 0xff;
header[3] = (size >> 8) & 0xff;
header[4] = size & 0xff;
header[5] = (duration >> 16) & 0xff;
header[6] = (duration >> 8) & 0xff;
header[7] = duration & 0xff;
ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
ffm_write_data(s, buf, size, pts, 0);
fst->pts += duration;
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);
if (!url_is_streamed(pb)) {
int64_t size;
/* update the write offset */
size = url_ftell(pb);
url_fseek(pb, 8, SEEK_SET);
put_be64(pb, size);
put_flush_packet(pb);
}
for(i=0;i<s->nb_streams;i++)
av_freep(&s->streams[i]->priv_data);
return 0;
}
#endif //CONFIG_ENCODERS
/* 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 (!ffm_nopts) {
/* XXX: I don't understand this test, so I disabled it for testing */
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_t *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);
retry_read:
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 (ffm->packet_end < ffm->packet)
av_abort();
/* 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 (url_ftell(pb) >= ffm->packet_size * 3) {
url_fseek(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 & 0x7ffff) < FFM_HEADER_SIZE)
av_abort();
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 void adjust_write_index(AVFormatContext *s)
{
FFMContext *ffm = s->priv_data;
ByteIOContext *pb = &s->pb;
int64_t pts;
//offset_t orig_write_index = ffm->write_index;
offset_t pos_min, pos_max;
int64_t pts_start;
offset_t ptr = url_ftell(pb);
pos_min = 0;
pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
pts_start = get_pts(s, pos_min);
pts = get_pts(s, pos_max);
if (pts - 100000 > pts_start)
return;
ffm->write_index = FFM_PACKET_SIZE;
pts_start = get_pts(s, pos_min);
pts = get_pts(s, pos_max);
if (pts - 100000 <= pts_start) {
while (1) {
offset_t newpos;
int64_t newpts;
newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
if (newpos == pos_min)
break;
newpts = get_pts(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 %lld to %lld: pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
//printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
url_fseek(pb, ptr, SEEK_SET);
}
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
FFMContext *ffm = s->priv_data;
AVStream *st;
FFMStream *fst;
ByteIOContext *pb = &s->pb;
AVCodecContext *codec;
int i, nb_streams;
uint32_t tag;
/* 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));
adjust_write_index(s);
} else {
ffm->file_size = (uint64_t_C(1) << 63) - 1;
}
nb_streams = get_be32(pb);
get_be32(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;
fst = av_mallocz(sizeof(FFMStream));
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);
st->quality = get_be32(pb);
codec->flags = get_be32(pb);
/* specific info */
switch(codec->codec_type) {
case CODEC_TYPE_VIDEO:
codec->frame_rate_base = get_be32(pb);
codec->frame_rate = get_be32(pb);
codec->width = get_be16(pb);
codec->height = get_be16(pb);
codec->gop_size = get_be16(pb);
codec->qmin = get_byte(pb);
codec->qmax = get_byte(pb);
codec->max_qdiff = get_byte(pb);
codec->qcompress = get_be16(pb) / 10000.0;
codec->qblur = get_be16(pb) / 10000.0;
codec->bit_rate_tolerance = get_be32(pb);
codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
codec->rc_max_rate = get_be32(pb);
codec->rc_min_rate = get_be32(pb);
codec->rc_buffer_size = get_be32(pb);
codec->i_quant_factor = get_be64_double(pb);
codec->b_quant_factor = get_be64_double(pb);
codec->i_quant_offset = get_be64_double(pb);
codec->b_quant_offset = get_be64_double(pb);
codec->dct_algo = get_be32(pb);
break;
case CODEC_TYPE_AUDIO:
codec->sample_rate = get_be32(pb);
codec->channels = get_le16(pb);
codec->frame_size = get_le16(pb);
break;
default:
goto fail;
}
}
/* 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) {
av_freep(&st->priv_data);
av_free(st);
}
}
return -1;
}
/* return < 0 if eof */
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int size;
FFMContext *ffm = s->priv_data;
int duration;
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;
}
duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
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;
}
pkt->pts = ffm->pts;
pkt->duration = duration;
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_t get_pts(AVFormatContext *s, offset_t pos)
{
ByteIOContext *pb = &s->pb;
int64_t 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_t wanted_pts)
{
FFMContext *ffm = s->priv_data;
offset_t pos_min, pos_max, pos;
int64_t 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_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_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_t 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 |= (int64_t)buf[i] << (56 - i * 8);
return pos;
}
void ffm_write_write_index(int fd, offset_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);
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];
av_freep(&st->priv_data);
}
return 0;
}
static int ffm_probe(AVProbeData *p)
{
if (p->buf_size >= 4 &&
p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
p->buf[3] == '1')
return AVPROBE_SCORE_MAX + 1;
return 0;
}
static AVInputFormat ffm_iformat = {
"ffm",
"ffm format",
sizeof(FFMContext),
ffm_probe,
ffm_read_header,
ffm_read_packet,
ffm_read_close,
ffm_seek,
};
#ifdef CONFIG_ENCODERS
static AVOutputFormat ffm_oformat = {
"ffm",
"ffm format",
"",
"ffm",
sizeof(FFMContext),
/* not really used */
CODEC_ID_MP2,
CODEC_ID_MPEG1VIDEO,
ffm_write_header,
ffm_write_packet,
ffm_write_trailer,
};
#endif //CONFIG_ENCODERS
int ffm_init(void)
{
av_register_input_format(&ffm_iformat);
#ifdef CONFIG_ENCODERS
av_register_output_format(&ffm_oformat);
#endif //CONFIG_ENCODERS
return 0;
}
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