FFmpeg/libavformat/ffmdec.c
Mans Rullgard 3b20eb25e7 avserver: move avserver-specific code from ffmdec.c to avserver.c
This way avserver only depends on the data structures of the ffm
demuxer, which it already does, and not also on private functions
being exported by the library.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2012-10-16 14:20:05 +01:00

482 lines
15 KiB
C

/*
* FFM (avserver 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 "libavutil/intfloat.h"
#include "avformat.h"
#include "internal.h"
#include "ffm.h"
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 int64_t 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);
return 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;
}
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)
{
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 = avformat_new_stream(s, NULL);
if (!st)
goto fail;
avpriv_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);
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_int2double(avio_rb64(pb));
codec->b_quant_factor = av_int2double(avio_rb64(pb));
codec->i_quant_offset = av_int2double(avio_rb64(pb));
codec->b_quant_offset = av_int2double(avio_rb64(pb));
codec->dct_algo = avio_rb32(pb);
codec->strict_std_compliance = avio_rb32(pb);
codec->max_b_frames = 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_int2double(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->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_int2double(avio_rb64(pb));
codec->qblur = av_int2double(avio_rb64(pb));
codec->max_qdiff = avio_rb32(pb);
codec->refs = 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);
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:
if (ffm_seek1(s, pos) < 0)
return -1;
/* 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 = {
.name = "ffm",
.long_name = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed)"),
.priv_data_size = sizeof(FFMContext),
.read_probe = ffm_probe,
.read_header = ffm_read_header,
.read_packet = ffm_read_packet,
.read_close = ffm_close,
.read_seek = ffm_seek,
};