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FFmpeg/libavformat/nutdec.c

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/*
* "NUT" Container Format demuxer
* Copyright (c) 2004-2006 Michael Niedermayer
* Copyright (c) 2003 Alex Beregszaszi
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/avstring.h"
#include "libavutil/avassert.h"
#include "libavutil/bswap.h"
#include "libavutil/dict.h"
#include "libavutil/mathematics.h"
#include "libavutil/tree.h"
#include "avio_internal.h"
#include "nut.h"
#define NUT_MAX_STREAMS 256 /* arbitrary sanity check value */
static int get_str(AVIOContext *bc, char *string, unsigned int maxlen)
{
unsigned int len = ffio_read_varlen(bc);
if (len && maxlen)
avio_read(bc, string, FFMIN(len, maxlen));
while (len > maxlen) {
avio_r8(bc);
len--;
}
if (maxlen)
string[FFMIN(len, maxlen - 1)] = 0;
if (maxlen == len)
return -1;
else
return 0;
}
static int64_t get_s(AVIOContext *bc)
{
int64_t v = ffio_read_varlen(bc) + 1;
if (v & 1)
return -(v >> 1);
else
return (v >> 1);
}
static uint64_t get_fourcc(AVIOContext *bc)
{
unsigned int len = ffio_read_varlen(bc);
if (len == 2)
return avio_rl16(bc);
else if (len == 4)
return avio_rl32(bc);
else
return -1;
}
#ifdef TRACE
static inline uint64_t get_v_trace(AVIOContext *bc, char *file,
char *func, int line)
{
uint64_t v = ffio_read_varlen(bc);
av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n",
v, v, file, func, line);
return v;
}
static inline int64_t get_s_trace(AVIOContext *bc, char *file,
char *func, int line)
{
int64_t v = get_s(bc);
av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n",
v, v, file, func, line);
return v;
}
static inline uint64_t get_vb_trace(AVIOContext *bc, char *file,
char *func, int line)
{
uint64_t v = get_vb(bc);
av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n",
v, v, file, func, line);
return v;
}
#define ffio_read_varlen(bc) get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_s(bc) get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_vb(bc) get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#endif
static int get_packetheader(NUTContext *nut, AVIOContext *bc,
int calculate_checksum, uint64_t startcode)
{
int64_t size;
// start = avio_tell(bc) - 8;
startcode = av_be2ne64(startcode);
startcode = ff_crc04C11DB7_update(0, (uint8_t*) &startcode, 8);
ffio_init_checksum(bc, ff_crc04C11DB7_update, startcode);
size = ffio_read_varlen(bc);
if (size > 4096)
avio_rb32(bc);
if (ffio_get_checksum(bc) && size > 4096)
return -1;
ffio_init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
return size;
}
static uint64_t find_any_startcode(AVIOContext *bc, int64_t pos)
{
uint64_t state = 0;
if (pos >= 0)
/* Note, this may fail if the stream is not seekable, but that should
* not matter, as in this case we simply start where we currently are */
avio_seek(bc, pos, SEEK_SET);
while (!url_feof(bc)) {
state = (state << 8) | avio_r8(bc);
if ((state >> 56) != 'N')
continue;
switch (state) {
case MAIN_STARTCODE:
case STREAM_STARTCODE:
case SYNCPOINT_STARTCODE:
case INFO_STARTCODE:
case INDEX_STARTCODE:
return state;
}
}
return 0;
}
/**
* Find the given startcode.
* @param code the startcode
* @param pos the start position of the search, or -1 if the current position
* @return the position of the startcode or -1 if not found
*/
static int64_t find_startcode(AVIOContext *bc, uint64_t code, int64_t pos)
{
for (;;) {
uint64_t startcode = find_any_startcode(bc, pos);
if (startcode == code)
return avio_tell(bc) - 8;
else if (startcode == 0)
return -1;
pos = -1;
}
}
static int nut_probe(AVProbeData *p)
{
int i;
uint64_t code = 0;
for (i = 0; i < p->buf_size; i++) {
code = (code << 8) | p->buf[i];
if (code == MAIN_STARTCODE)
return AVPROBE_SCORE_MAX;
}
return 0;
}
#define GET_V(dst, check) \
tmp = ffio_read_varlen(bc); \
if (!(check)) { \
av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp); \
return -1; \
} \
dst = tmp;
static int skip_reserved(AVIOContext *bc, int64_t pos)
{
pos -= avio_tell(bc);
if (pos < 0) {
avio_seek(bc, pos, SEEK_CUR);
return -1;
} else {
while (pos--)
avio_r8(bc);
return 0;
}
}
static int decode_main_header(NUTContext *nut)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
uint64_t tmp, end;
unsigned int stream_count;
int i, j, count;
int tmp_stream, tmp_mul, tmp_pts, tmp_size, tmp_res, tmp_head_idx;
end = get_packetheader(nut, bc, 1, MAIN_STARTCODE);
end += avio_tell(bc);
GET_V(tmp, tmp >= 2 && tmp <= 3)
GET_V(stream_count, tmp > 0 && tmp <= NUT_MAX_STREAMS)
nut->max_distance = ffio_read_varlen(bc);
if (nut->max_distance > 65536) {
av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
nut->max_distance = 65536;
}
GET_V(nut->time_base_count, tmp > 0 && tmp < INT_MAX / sizeof(AVRational))
nut->time_base = av_malloc(nut->time_base_count * sizeof(AVRational));
for (i = 0; i < nut->time_base_count; i++) {
GET_V(nut->time_base[i].num, tmp > 0 && tmp < (1ULL << 31))
GET_V(nut->time_base[i].den, tmp > 0 && tmp < (1ULL << 31))
if (av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1) {
av_log(s, AV_LOG_ERROR, "time base invalid\n");
return AVERROR_INVALIDDATA;
}
}
tmp_pts = 0;
tmp_mul = 1;
tmp_stream = 0;
tmp_head_idx = 0;
for (i = 0; i < 256;) {
int tmp_flags = ffio_read_varlen(bc);
int tmp_fields = ffio_read_varlen(bc);
if (tmp_fields > 0)
tmp_pts = get_s(bc);
if (tmp_fields > 1)
tmp_mul = ffio_read_varlen(bc);
if (tmp_fields > 2)
tmp_stream = ffio_read_varlen(bc);
if (tmp_fields > 3)
tmp_size = ffio_read_varlen(bc);
else
tmp_size = 0;
if (tmp_fields > 4)
tmp_res = ffio_read_varlen(bc);
else
tmp_res = 0;
if (tmp_fields > 5)
count = ffio_read_varlen(bc);
else
count = tmp_mul - tmp_size;
if (tmp_fields > 6)
get_s(bc);
if (tmp_fields > 7)
tmp_head_idx = ffio_read_varlen(bc);
while (tmp_fields-- > 8)
ffio_read_varlen(bc);
if (count == 0 || i + count > 256) {
av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
return AVERROR_INVALIDDATA;
}
if (tmp_stream >= stream_count) {
av_log(s, AV_LOG_ERROR, "illegal stream number\n");
return AVERROR_INVALIDDATA;
}
for (j = 0; j < count; j++, i++) {
if (i == 'N') {
nut->frame_code[i].flags = FLAG_INVALID;
j--;
continue;
}
nut->frame_code[i].flags = tmp_flags;
nut->frame_code[i].pts_delta = tmp_pts;
nut->frame_code[i].stream_id = tmp_stream;
nut->frame_code[i].size_mul = tmp_mul;
nut->frame_code[i].size_lsb = tmp_size + j;
nut->frame_code[i].reserved_count = tmp_res;
nut->frame_code[i].header_idx = tmp_head_idx;
}
}
av_assert0(nut->frame_code['N'].flags == FLAG_INVALID);
if (end > avio_tell(bc) + 4) {
int rem = 1024;
GET_V(nut->header_count, tmp < 128U)
nut->header_count++;
for (i = 1; i < nut->header_count; i++) {
uint8_t *hdr;
GET_V(nut->header_len[i], tmp > 0 && tmp < 256);
rem -= nut->header_len[i];
if (rem < 0) {
av_log(s, AV_LOG_ERROR, "invalid elision header\n");
return AVERROR_INVALIDDATA;
}
hdr = av_malloc(nut->header_len[i]);
if (!hdr)
return AVERROR(ENOMEM);
avio_read(bc, hdr, nut->header_len[i]);
nut->header[i] = hdr;
}
av_assert0(nut->header_len[0] == 0);
}
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
return AVERROR_INVALIDDATA;
}
nut->stream = av_mallocz(sizeof(StreamContext) * stream_count);
for (i = 0; i < stream_count; i++)
avformat_new_stream(s, NULL);
return 0;
}
static int decode_stream_header(NUTContext *nut)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
StreamContext *stc;
int class, stream_id;
uint64_t tmp, end;
AVStream *st;
end = get_packetheader(nut, bc, 1, STREAM_STARTCODE);
end += avio_tell(bc);
GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
stc = &nut->stream[stream_id];
st = s->streams[stream_id];
if (!st)
return AVERROR(ENOMEM);
class = ffio_read_varlen(bc);
tmp = get_fourcc(bc);
st->codec->codec_tag = tmp;
switch (class) {
case 0:
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = av_codec_get_id((const AVCodecTag * const []) {
ff_codec_bmp_tags,
ff_nut_video_tags,
0
},
tmp);
break;
case 1:
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, tmp);
break;
case 2:
st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codec->codec_id = ff_codec_get_id(ff_nut_subtitle_tags, tmp);
break;
case 3:
st->codec->codec_type = AVMEDIA_TYPE_DATA;
break;
default:
av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
return -1;
}
if (class < 3 && st->codec->codec_id == CODEC_ID_NONE)
av_log(s, AV_LOG_ERROR,
"Unknown codec tag '0x%04x' for stream number %d\n",
(unsigned int) tmp, stream_id);
GET_V(stc->time_base_id, tmp < nut->time_base_count);
GET_V(stc->msb_pts_shift, tmp < 16);
stc->max_pts_distance = ffio_read_varlen(bc);
GET_V(stc->decode_delay, tmp < 1000); // sanity limit, raise this if Moore's law is true
st->codec->has_b_frames = stc->decode_delay;
ffio_read_varlen(bc); // stream flags
GET_V(st->codec->extradata_size, tmp < (1 << 30));
if (st->codec->extradata_size) {
st->codec->extradata = av_mallocz(st->codec->extradata_size +
FF_INPUT_BUFFER_PADDING_SIZE);
avio_read(bc, st->codec->extradata, st->codec->extradata_size);
}
if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
GET_V(st->codec->width, tmp > 0)
GET_V(st->codec->height, tmp > 0)
st->sample_aspect_ratio.num = ffio_read_varlen(bc);
st->sample_aspect_ratio.den = ffio_read_varlen(bc);
if ((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)) {
av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n",
st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
return -1;
}
ffio_read_varlen(bc); /* csp type */
} else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
GET_V(st->codec->sample_rate, tmp > 0)
ffio_read_varlen(bc); // samplerate_den
GET_V(st->codec->channels, tmp > 0)
}
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR,
"stream header %d checksum mismatch\n", stream_id);
return -1;
}
stc->time_base = &nut->time_base[stc->time_base_id];
avpriv_set_pts_info(s->streams[stream_id], 63, stc->time_base->num,
stc->time_base->den);
return 0;
}
static void set_disposition_bits(AVFormatContext *avf, char *value,
int stream_id)
{
int flag = 0, i;
for (i = 0; ff_nut_dispositions[i].flag; ++i)
if (!strcmp(ff_nut_dispositions[i].str, value))
flag = ff_nut_dispositions[i].flag;
if (!flag)
av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
for (i = 0; i < avf->nb_streams; ++i)
if (stream_id == i || stream_id == -1)
avf->streams[i]->disposition |= flag;
}
static int decode_info_header(NUTContext *nut)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
uint64_t tmp, chapter_start, chapter_len;
unsigned int stream_id_plus1, count;
int chapter_id, i;
int64_t value, end;
char name[256], str_value[1024], type_str[256];
const char *type;
AVChapter *chapter = NULL;
AVStream *st = NULL;
AVDictionary **metadata = NULL;
end = get_packetheader(nut, bc, 1, INFO_STARTCODE);
end += avio_tell(bc);
GET_V(stream_id_plus1, tmp <= s->nb_streams)
chapter_id = get_s(bc);
chapter_start = ffio_read_varlen(bc);
chapter_len = ffio_read_varlen(bc);
count = ffio_read_varlen(bc);
if (chapter_id && !stream_id_plus1) {
int64_t start = chapter_start / nut->time_base_count;
chapter = avpriv_new_chapter(s, chapter_id,
nut->time_base[chapter_start %
nut->time_base_count],
start, start + chapter_len, NULL);
metadata = &chapter->metadata;
} else if (stream_id_plus1) {
st = s->streams[stream_id_plus1 - 1];
metadata = &st->metadata;
} else
metadata = &s->metadata;
for (i = 0; i < count; i++) {
get_str(bc, name, sizeof(name));
value = get_s(bc);
if (value == -1) {
type = "UTF-8";
get_str(bc, str_value, sizeof(str_value));
} else if (value == -2) {
get_str(bc, type_str, sizeof(type_str));
type = type_str;
get_str(bc, str_value, sizeof(str_value));
} else if (value == -3) {
type = "s";
value = get_s(bc);
} else if (value == -4) {
type = "t";
value = ffio_read_varlen(bc);
} else if (value < -4) {
type = "r";
get_s(bc);
} else {
type = "v";
}
if (stream_id_plus1 > s->nb_streams) {
av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
continue;
}
if (!strcmp(type, "UTF-8")) {
if (chapter_id == 0 && !strcmp(name, "Disposition")) {
set_disposition_bits(s, str_value, stream_id_plus1 - 1);
continue;
}
if (metadata && av_strcasecmp(name, "Uses") &&
av_strcasecmp(name, "Depends") && av_strcasecmp(name, "Replaces"))
av_dict_set(metadata, name, str_value, 0);
}
}
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
return -1;
}
return 0;
}
static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
int64_t end, tmp;
nut->last_syncpoint_pos = avio_tell(bc) - 8;
end = get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
end += avio_tell(bc);
tmp = ffio_read_varlen(bc);
*back_ptr = nut->last_syncpoint_pos - 16 * ffio_read_varlen(bc);
if (*back_ptr < 0)
return -1;
ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count],
tmp / nut->time_base_count);
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
return -1;
}
*ts = tmp / s->nb_streams *
av_q2d(nut->time_base[tmp % s->nb_streams]) * AV_TIME_BASE;
ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
return 0;
}
static int find_and_decode_index(NUTContext *nut)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
uint64_t tmp, end;
int i, j, syncpoint_count;
int64_t filesize = avio_size(bc);
int64_t *syncpoints;
int8_t *has_keyframe;
int ret = -1;
avio_seek(bc, filesize - 12, SEEK_SET);
avio_seek(bc, filesize - avio_rb64(bc), SEEK_SET);
if (avio_rb64(bc) != INDEX_STARTCODE) {
av_log(s, AV_LOG_ERROR, "no index at the end\n");
return -1;
}
end = get_packetheader(nut, bc, 1, INDEX_STARTCODE);
end += avio_tell(bc);
ffio_read_varlen(bc); // max_pts
GET_V(syncpoint_count, tmp < INT_MAX / 8 && tmp > 0)
syncpoints = av_malloc(sizeof(int64_t) * syncpoint_count);
has_keyframe = av_malloc(sizeof(int8_t) * (syncpoint_count + 1));
for (i = 0; i < syncpoint_count; i++) {
syncpoints[i] = ffio_read_varlen(bc);
if (syncpoints[i] <= 0)
goto fail;
if (i)
syncpoints[i] += syncpoints[i - 1];
}
for (i = 0; i < s->nb_streams; i++) {
int64_t last_pts = -1;
for (j = 0; j < syncpoint_count;) {
uint64_t x = ffio_read_varlen(bc);
int type = x & 1;
int n = j;
x >>= 1;
if (type) {
int flag = x & 1;
x >>= 1;
if (n + x >= syncpoint_count + 1) {
av_log(s, AV_LOG_ERROR, "index overflow A\n");
goto fail;
}
while (x--)
has_keyframe[n++] = flag;
has_keyframe[n++] = !flag;
} else {
while (x != 1) {
if (n >= syncpoint_count + 1) {
av_log(s, AV_LOG_ERROR, "index overflow B\n");
goto fail;
}
has_keyframe[n++] = x & 1;
x >>= 1;
}
}
if (has_keyframe[0]) {
av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
goto fail;
}
av_assert0(n <= syncpoint_count + 1);
for (; j < n && j < syncpoint_count; j++) {
if (has_keyframe[j]) {
uint64_t B, A = ffio_read_varlen(bc);
if (!A) {
A = ffio_read_varlen(bc);
B = ffio_read_varlen(bc);
// eor_pts[j][i] = last_pts + A + B
} else
B = 0;
av_add_index_entry(s->streams[i], 16 * syncpoints[j - 1],
last_pts + A, 0, 0, AVINDEX_KEYFRAME);
last_pts += A + B;
}
}
}
}
if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {
av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
goto fail;
}
ret = 0;
fail:
av_free(syncpoints);
av_free(has_keyframe);
return ret;
}
static int nut_read_header(AVFormatContext *s)
{
NUTContext *nut = s->priv_data;
AVIOContext *bc = s->pb;
int64_t pos;
int initialized_stream_count;
nut->avf = s;
/* main header */
pos = 0;
do {
pos = find_startcode(bc, MAIN_STARTCODE, pos) + 1;
if (pos < 0 + 1) {
av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
return AVERROR_INVALIDDATA;
}
} while (decode_main_header(nut) < 0);
/* stream headers */
pos = 0;
for (initialized_stream_count = 0; initialized_stream_count < s->nb_streams;) {
pos = find_startcode(bc, STREAM_STARTCODE, pos) + 1;
if (pos < 0 + 1) {
av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
return AVERROR_INVALIDDATA;
}
if (decode_stream_header(nut) >= 0)
initialized_stream_count++;
}
/* info headers */
pos = 0;
for (;;) {
uint64_t startcode = find_any_startcode(bc, pos);
pos = avio_tell(bc);
if (startcode == 0) {
av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
return AVERROR_INVALIDDATA;
} else if (startcode == SYNCPOINT_STARTCODE) {
nut->next_startcode = startcode;
break;
} else if (startcode != INFO_STARTCODE) {
continue;
}
decode_info_header(nut);
}
s->data_offset = pos - 8;
if (bc->seekable) {
int64_t orig_pos = avio_tell(bc);
find_and_decode_index(nut);
avio_seek(bc, orig_pos, SEEK_SET);
}
av_assert0(nut->next_startcode == SYNCPOINT_STARTCODE);
ff_metadata_conv_ctx(s, NULL, ff_nut_metadata_conv);
return 0;
}
static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id,
uint8_t *header_idx, int frame_code)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
StreamContext *stc;
int size, flags, size_mul, pts_delta, i, reserved_count;
uint64_t tmp;
if (avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance) {
av_log(s, AV_LOG_ERROR,
"Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n",
avio_tell(bc), nut->last_syncpoint_pos, nut->max_distance);
return AVERROR_INVALIDDATA;
}
flags = nut->frame_code[frame_code].flags;
size_mul = nut->frame_code[frame_code].size_mul;
size = nut->frame_code[frame_code].size_lsb;
*stream_id = nut->frame_code[frame_code].stream_id;
pts_delta = nut->frame_code[frame_code].pts_delta;
reserved_count = nut->frame_code[frame_code].reserved_count;
*header_idx = nut->frame_code[frame_code].header_idx;
if (flags & FLAG_INVALID)
return AVERROR_INVALIDDATA;
if (flags & FLAG_CODED)
flags ^= ffio_read_varlen(bc);
if (flags & FLAG_STREAM_ID) {
GET_V(*stream_id, tmp < s->nb_streams)
}
stc = &nut->stream[*stream_id];
if (flags & FLAG_CODED_PTS) {
int coded_pts = ffio_read_varlen(bc);
// FIXME check last_pts validity?
if (coded_pts < (1 << stc->msb_pts_shift)) {
*pts = ff_lsb2full(stc, coded_pts);
} else
*pts = coded_pts - (1 << stc->msb_pts_shift);
} else
*pts = stc->last_pts + pts_delta;
if (flags & FLAG_SIZE_MSB)
size += size_mul * ffio_read_varlen(bc);
if (flags & FLAG_MATCH_TIME)
get_s(bc);
if (flags & FLAG_HEADER_IDX)
*header_idx = ffio_read_varlen(bc);
if (flags & FLAG_RESERVED)
reserved_count = ffio_read_varlen(bc);
for (i = 0; i < reserved_count; i++)
ffio_read_varlen(bc);
if (*header_idx >= (unsigned)nut->header_count) {
av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
return AVERROR_INVALIDDATA;
}
if (size > 4096)
*header_idx = 0;
size -= nut->header_len[*header_idx];
if (flags & FLAG_CHECKSUM) {
avio_rb32(bc); // FIXME check this
} else if (size > 2 * nut->max_distance || FFABS(stc->last_pts - *pts) >
stc->max_pts_distance) {
av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
return AVERROR_INVALIDDATA;
}
stc->last_pts = *pts;
stc->last_flags = flags;
return size;
}
static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code)
{
AVFormatContext *s = nut->avf;
AVIOContext *bc = s->pb;
int size, stream_id, discard;
int64_t pts, last_IP_pts;
StreamContext *stc;
uint8_t header_idx;
size = decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
if (size < 0)
return size;
stc = &nut->stream[stream_id];
if (stc->last_flags & FLAG_KEY)
stc->skip_until_key_frame = 0;
discard = s->streams[stream_id]->discard;
last_IP_pts = s->streams[stream_id]->last_IP_pts;
if ((discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY)) ||
(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE &&
last_IP_pts > pts) ||
discard >= AVDISCARD_ALL ||
stc->skip_until_key_frame) {
avio_skip(bc, size);
return 1;
}
av_new_packet(pkt, size + nut->header_len[header_idx]);
memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
pkt->pos = avio_tell(bc); // FIXME
avio_read(bc, pkt->data + nut->header_len[header_idx], size);
pkt->stream_index = stream_id;
if (stc->last_flags & FLAG_KEY)
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->pts = pts;
return 0;
}
static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
{
NUTContext *nut = s->priv_data;
AVIOContext *bc = s->pb;
int i, frame_code = 0, ret, skip;
int64_t ts, back_ptr;
for (;;) {
int64_t pos = avio_tell(bc);
uint64_t tmp = nut->next_startcode;
nut->next_startcode = 0;
if (tmp) {
pos -= 8;
} else {
frame_code = avio_r8(bc);
if (url_feof(bc))
return -1;
if (frame_code == 'N') {
tmp = frame_code;
for (i = 1; i < 8; i++)
tmp = (tmp << 8) + avio_r8(bc);
}
}
switch (tmp) {
case MAIN_STARTCODE:
case STREAM_STARTCODE:
case INDEX_STARTCODE:
skip = get_packetheader(nut, bc, 0, tmp);
avio_skip(bc, skip);
break;
case INFO_STARTCODE:
if (decode_info_header(nut) < 0)
goto resync;
break;
case SYNCPOINT_STARTCODE:
if (decode_syncpoint(nut, &ts, &back_ptr) < 0)
goto resync;
frame_code = avio_r8(bc);
case 0:
ret = decode_frame(nut, pkt, frame_code);
if (ret == 0)
return 0;
else if (ret == 1) // OK but discard packet
break;
default:
resync:
av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
tmp = find_any_startcode(bc, nut->last_syncpoint_pos + 1);
if (tmp == 0)
return AVERROR_INVALIDDATA;
av_log(s, AV_LOG_DEBUG, "sync\n");
nut->next_startcode = tmp;
}
}
}
static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,
int64_t *pos_arg, int64_t pos_limit)
{
NUTContext *nut = s->priv_data;
AVIOContext *bc = s->pb;
int64_t pos, pts, back_ptr;
av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n",
stream_index, *pos_arg, pos_limit);
pos = *pos_arg;
do {
pos = find_startcode(bc, SYNCPOINT_STARTCODE, pos) + 1;
if (pos < 1) {
av_assert0(nut->next_startcode == 0);
av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
return AV_NOPTS_VALUE;
}
} while (decode_syncpoint(nut, &pts, &back_ptr) < 0);
*pos_arg = pos - 1;
av_assert0(nut->last_syncpoint_pos == *pos_arg);
av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts, back_ptr);
if (stream_index == -2)
return back_ptr;
av_assert0(stream_index == -1);
return pts;
}
static int read_seek(AVFormatContext *s, int stream_index,
int64_t pts, int flags)
{
NUTContext *nut = s->priv_data;
AVStream *st = s->streams[stream_index];
Syncpoint dummy = { .ts = pts * av_q2d(st->time_base) * AV_TIME_BASE };
Syncpoint nopts_sp = { .ts = AV_NOPTS_VALUE, .back_ptr = AV_NOPTS_VALUE };
Syncpoint *sp, *next_node[2] = { &nopts_sp, &nopts_sp };
int64_t pos, pos2, ts;
int i;
if (st->index_entries) {
int index = av_index_search_timestamp(st, pts, flags);
if (index < 0)
return -1;
pos2 = st->index_entries[index].pos;
ts = st->index_entries[index].timestamp;
} else {
av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,
(void **) next_node);
av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n",
next_node[0]->pos, next_node[1]->pos, next_node[0]->ts,
next_node[1]->ts);
pos = ff_gen_search(s, -1, dummy.ts, next_node[0]->pos,
next_node[1]->pos, next_node[1]->pos,
next_node[0]->ts, next_node[1]->ts,
AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
if (!(flags & AVSEEK_FLAG_BACKWARD)) {
dummy.pos = pos + 16;
next_node[1] = &nopts_sp;
av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
(void **) next_node);
pos2 = ff_gen_search(s, -2, dummy.pos, next_node[0]->pos,
next_node[1]->pos, next_node[1]->pos,
next_node[0]->back_ptr, next_node[1]->back_ptr,
flags, &ts, nut_read_timestamp);
if (pos2 >= 0)
pos = pos2;
// FIXME dir but I think it does not matter
}
dummy.pos = pos;
sp = av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
NULL);
av_assert0(sp);
pos2 = sp->back_ptr - 15;
}
av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
pos = find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
avio_seek(s->pb, pos, SEEK_SET);
av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
if (pos2 > pos || pos2 + 15 < pos)
av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
for (i = 0; i < s->nb_streams; i++)
nut->stream[i].skip_until_key_frame = 1;
return 0;
}
static int nut_read_close(AVFormatContext *s)
{
NUTContext *nut = s->priv_data;
int i;
av_freep(&nut->time_base);
av_freep(&nut->stream);
ff_nut_free_sp(nut);
for (i = 1; i < nut->header_count; i++)
av_freep(&nut->header[i]);
return 0;
}
AVInputFormat ff_nut_demuxer = {
.name = "nut",
.long_name = NULL_IF_CONFIG_SMALL("NUT format"),
.flags = AVFMT_SEEK_TO_PTS,
.priv_data_size = sizeof(NUTContext),
.read_probe = nut_probe,
.read_header = nut_read_header,
.read_packet = nut_read_packet,
.read_close = nut_read_close,
.read_seek = read_seek,
.extensions = "nut",
.codec_tag = (const AVCodecTag * const []) {
ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags,
ff_nut_subtitle_tags, 0
},
};