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FFmpeg/libavformat/dhav.c
Andreas Rheinhardt d8cad01805 avformat/dhav: Check amount read 
Prevents potential use of uninitialized data in the following
memcmp().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-05-25 13:51:27 +02:00

483 lines
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/*
* DHAV demuxer
*
* Copyright (c) 2018 Paul B Mahol
*
* 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 <time.h>
#include "libavutil/mem.h"
#include "libavutil/parseutils.h"
#include "avio_internal.h"
#include "avformat.h"
#include "demux.h"
#include "internal.h"
typedef struct DHAVContext {
unsigned type;
unsigned subtype;
unsigned channel;
unsigned frame_subnumber;
unsigned frame_number;
unsigned date;
unsigned timestamp;
int width, height;
int video_codec;
int frame_rate;
int audio_channels;
int audio_codec;
int sample_rate;
int64_t last_good_pos;
int64_t duration;
int video_stream_index;
int audio_stream_index;
} DHAVContext;
typedef struct DHAVStream {
int64_t last_frame_number;
int64_t last_timestamp;
int64_t last_time;
int64_t pts;
} DHAVStream;
static int dhav_probe(const AVProbeData *p)
{
if (!memcmp(p->buf, "DAHUA", 5))
return AVPROBE_SCORE_MAX;
if (memcmp(p->buf, "DHAV", 4))
return 0;
if (p->buf[4] == 0xf0 ||
p->buf[4] == 0xf1 ||
p->buf[4] == 0xfc ||
p->buf[4] == 0xfd)
return AVPROBE_SCORE_MAX;
return 0;
}
static const uint32_t sample_rates[] = {
8000, 4000, 8000, 11025, 16000,
20000, 22050, 32000, 44100, 48000,
96000, 192000, 64000,
};
static int parse_ext(AVFormatContext *s, int length)
{
DHAVContext *dhav = s->priv_data;
int64_t ret = 0;
while (length > 0) {
int type = avio_r8(s->pb);
int index;
switch (type) {
case 0x80:
ret = avio_skip(s->pb, 1);
dhav->width = 8 * avio_r8(s->pb);
dhav->height = 8 * avio_r8(s->pb);
length -= 4;
break;
case 0x81:
ret = avio_skip(s->pb, 1);
dhav->video_codec = avio_r8(s->pb);
dhav->frame_rate = avio_r8(s->pb);
length -= 4;
break;
case 0x82:
ret = avio_skip(s->pb, 3);
dhav->width = avio_rl16(s->pb);
dhav->height = avio_rl16(s->pb);
length -= 8;
break;
case 0x83:
dhav->audio_channels = avio_r8(s->pb);
dhav->audio_codec = avio_r8(s->pb);
index = avio_r8(s->pb);
if (index < FF_ARRAY_ELEMS(sample_rates)) {
dhav->sample_rate = sample_rates[index];
} else {
dhav->sample_rate = 8000;
}
length -= 4;
break;
case 0x88:
ret = avio_skip(s->pb, 7);
length -= 8;
break;
case 0x8c:
ret = avio_skip(s->pb, 1);
dhav->audio_channels = avio_r8(s->pb);
dhav->audio_codec = avio_r8(s->pb);
index = avio_r8(s->pb);
if (index < FF_ARRAY_ELEMS(sample_rates)) {
dhav->sample_rate = sample_rates[index];
} else {
dhav->sample_rate = 8000;
}
ret = avio_skip(s->pb, 3);
length -= 8;
break;
case 0x91:
case 0x92:
case 0x93:
case 0x95:
case 0x9a:
case 0x9b: // sample aspect ratio
case 0xb3:
ret = avio_skip(s->pb, 7);
length -= 8;
break;
case 0x84:
case 0x85:
case 0x8b:
case 0x94:
case 0x96:
case 0xa0:
case 0xb2:
case 0xb4:
ret = avio_skip(s->pb, 3);
length -= 4;
break;
default:
av_log(s, AV_LOG_INFO, "Unknown type: %X, skipping rest of header.\n", type);
ret = avio_skip(s->pb, length - 1);
length = 0;
}
if (ret < 0)
return ret;
}
return 0;
}
static int read_chunk(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
int frame_length, ext_length;
int64_t start, end, ret;
if (avio_feof(s->pb))
return AVERROR_EOF;
while (avio_r8(s->pb) != 'D' || avio_r8(s->pb) != 'H' || avio_r8(s->pb) != 'A' || avio_r8(s->pb) != 'V') {
if (avio_feof(s->pb))
return AVERROR_EOF;
}
start = avio_tell(s->pb) - 4;
dhav->last_good_pos = start;
dhav->type = avio_r8(s->pb);
dhav->subtype = avio_r8(s->pb);
dhav->channel = avio_r8(s->pb);
dhav->frame_subnumber = avio_r8(s->pb);
dhav->frame_number = avio_rl32(s->pb);
frame_length = avio_rl32(s->pb);
dhav->date = avio_rl32(s->pb);
if (frame_length < 24)
return AVERROR_INVALIDDATA;
if (dhav->type == 0xf1) {
ret = avio_skip(s->pb, frame_length - 20);
return ret < 0 ? ret : 0;
}
dhav->timestamp = avio_rl16(s->pb);
ext_length = avio_r8(s->pb);
avio_skip(s->pb, 1); // checksum
ret = parse_ext(s, ext_length);
if (ret < 0)
return ret;
end = avio_tell(s->pb);
return frame_length - 8 - (end - start);
}
static void get_timeinfo(unsigned date, struct tm *timeinfo)
{
int year, month, day, hour, min, sec;
sec = date & 0x3F;
min = (date >> 6) & 0x3F;
hour = (date >> 12) & 0x1F;
day = (date >> 17) & 0x1F;
month = (date >> 22) & 0x0F;
year = ((date >> 26) & 0x3F) + 2000;
timeinfo->tm_year = year - 1900;
timeinfo->tm_mon = month - 1;
timeinfo->tm_mday = day;
timeinfo->tm_hour = hour;
timeinfo->tm_min = min;
timeinfo->tm_sec = sec;
}
static int64_t get_duration(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
int64_t start_pos = avio_tell(s->pb);
int64_t start = 0, end = 0;
struct tm timeinfo;
int max_interations = 100000;
if (!s->pb->seekable)
return 0;
avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
while (avio_tell(s->pb) > 12 && max_interations--) {
if (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
int64_t seek_back = avio_rl32(s->pb);
avio_seek(s->pb, -seek_back, SEEK_CUR);
read_chunk(s);
get_timeinfo(dhav->date, &timeinfo);
end = av_timegm(&timeinfo) * 1000LL;
break;
} else {
avio_seek(s->pb, -12, SEEK_CUR);
}
}
avio_seek(s->pb, start_pos, SEEK_SET);
read_chunk(s);
get_timeinfo(dhav->date, &timeinfo);
start = av_timegm(&timeinfo) * 1000LL;
avio_seek(s->pb, start_pos, SEEK_SET);
return end - start;
}
static int dhav_read_header(AVFormatContext *s)
{
DHAVContext *dhav = s->priv_data;
uint8_t signature[5];
int ret = ffio_ensure_seekback(s->pb, 5);
if (ret < 0)
return ret;
ret = ffio_read_size(s->pb, signature, sizeof(signature));
if (ret < 0)
return ret;
if (!memcmp(signature, "DAHUA", 5)) {
avio_skip(s->pb, 0x400 - 5);
dhav->last_good_pos = avio_tell(s->pb);
} else {
if (!memcmp(signature, "DHAV", 4)) {
avio_seek(s->pb, -5, SEEK_CUR);
dhav->last_good_pos = avio_tell(s->pb);
} else if (s->pb->seekable) {
avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
while (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
int seek_back;
seek_back = avio_rl32(s->pb) + 8;
if (seek_back < 9)
break;
dhav->last_good_pos = avio_tell(s->pb);
avio_seek(s->pb, -seek_back, SEEK_CUR);
}
avio_seek(s->pb, dhav->last_good_pos, SEEK_SET);
}
}
dhav->duration = get_duration(s);
dhav->last_good_pos = avio_tell(s->pb);
s->ctx_flags |= AVFMTCTX_NOHEADER;
dhav->video_stream_index = -1;
dhav->audio_stream_index = -1;
return 0;
}
static int64_t get_pts(AVFormatContext *s, int stream_index)
{
DHAVStream *dst = s->streams[stream_index]->priv_data;
DHAVContext *dhav = s->priv_data;
struct tm timeinfo;
time_t t;
get_timeinfo(dhav->date, &timeinfo);
t = av_timegm(&timeinfo);
if (dst->last_time == t) {
int64_t diff = dhav->timestamp - dst->last_timestamp;
if (diff < 0)
diff += 65535;
if (diff == 0 && dhav->frame_rate)
diff = av_rescale(dhav->frame_number - dst->last_frame_number, 1000, dhav->frame_rate);
dst->pts += diff;
} else {
dst->pts = t * 1000LL;
}
dst->last_time = t;
dst->last_timestamp = dhav->timestamp;
dst->last_frame_number = dhav->frame_number;
return dst->pts;
}
static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
{
DHAVContext *dhav = s->priv_data;
int size, ret, stream_index;
retry:
while ((ret = read_chunk(s)) == 0)
;
if (ret < 0)
return ret;
if (dhav->type == 0xfd && dhav->video_stream_index == -1) {
AVStream *st = avformat_new_stream(s, NULL);
DHAVStream *dst;
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
switch (dhav->video_codec) {
case 0x1: st->codecpar->codec_id = AV_CODEC_ID_MPEG4; break;
case 0x3: st->codecpar->codec_id = AV_CODEC_ID_MJPEG; break;
case 0x2:
case 0x4:
case 0x8: st->codecpar->codec_id = AV_CODEC_ID_H264; break;
case 0xc: st->codecpar->codec_id = AV_CODEC_ID_HEVC; break;
default: avpriv_request_sample(s, "Unknown video codec %X", dhav->video_codec);
}
st->duration = dhav->duration;
st->codecpar->width = dhav->width;
st->codecpar->height = dhav->height;
st->avg_frame_rate.num = dhav->frame_rate;
st->avg_frame_rate.den = 1;
st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
if (!st->priv_data)
return AVERROR(ENOMEM);
dst->last_time = AV_NOPTS_VALUE;
dhav->video_stream_index = st->index;
avpriv_set_pts_info(st, 64, 1, 1000);
} else if (dhav->type == 0xf0 && dhav->audio_stream_index == -1) {
AVStream *st = avformat_new_stream(s, NULL);
DHAVStream *dst;
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
switch (dhav->audio_codec) {
case 0x07: st->codecpar->codec_id = AV_CODEC_ID_PCM_S8; break;
case 0x0c: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE; break;
case 0x10: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE; break;
case 0x0a: st->codecpar->codec_id = AV_CODEC_ID_PCM_MULAW; break;
case 0x16: st->codecpar->codec_id = AV_CODEC_ID_PCM_MULAW; break;
case 0x0e: st->codecpar->codec_id = AV_CODEC_ID_PCM_ALAW; break;
case 0x1a: st->codecpar->codec_id = AV_CODEC_ID_AAC; break;
case 0x1f: st->codecpar->codec_id = AV_CODEC_ID_MP2; break;
case 0x21: st->codecpar->codec_id = AV_CODEC_ID_MP3; break;
case 0x0d: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_MS; break;
default: avpriv_request_sample(s, "Unknown audio codec %X", dhav->audio_codec);
}
st->duration = dhav->duration;
st->codecpar->ch_layout.nb_channels = dhav->audio_channels;
st->codecpar->sample_rate = dhav->sample_rate;
st->priv_data = dst = av_mallocz(sizeof(DHAVStream));
if (!st->priv_data)
return AVERROR(ENOMEM);
dst->last_time = AV_NOPTS_VALUE;
dhav->audio_stream_index = st->index;
avpriv_set_pts_info(st, 64, 1, 1000);
}
stream_index = dhav->type == 0xf0 ? dhav->audio_stream_index : dhav->video_stream_index;
if (stream_index < 0) {
avio_skip(s->pb, ret);
if (avio_rl32(s->pb) == MKTAG('d','h','a','v'))
avio_skip(s->pb, 4);
goto retry;
}
size = ret;
ret = av_get_packet(s->pb, pkt, size);
if (ret < 0)
return ret;
pkt->stream_index = stream_index;
if (dhav->type != 0xfc)
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->duration = 1;
if (pkt->stream_index >= 0)
pkt->pts = get_pts(s, pkt->stream_index);
pkt->pos = dhav->last_good_pos;
if (avio_rl32(s->pb) == MKTAG('d','h','a','v'))
avio_skip(s->pb, 4);
return ret;
}
static int dhav_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
DHAVContext *dhav = s->priv_data;
AVStream *st = s->streams[stream_index];
FFStream *const sti = ffstream(st);
int index = av_index_search_timestamp(st, timestamp, flags);
int64_t pts;
if (index < 0)
return -1;
pts = sti->index_entries[index].timestamp;
if (pts < timestamp)
return AVERROR(EAGAIN);
if (avio_seek(s->pb, sti->index_entries[index].pos, SEEK_SET) < 0)
return -1;
for (int n = 0; n < s->nb_streams; n++) {
AVStream *st = s->streams[n];
DHAVStream *dst = st->priv_data;
dst->pts = pts;
dst->last_time = AV_NOPTS_VALUE;
}
dhav->last_good_pos = avio_tell(s->pb);
return 0;
}
const FFInputFormat ff_dhav_demuxer = {
.p.name = "dhav",
.p.long_name = NULL_IF_CONFIG_SMALL("Video DAV"),
.p.extensions = "dav",
.p.flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_TS_DISCONT | AVFMT_TS_NONSTRICT | AVFMT_SEEK_TO_PTS,
.priv_data_size = sizeof(DHAVContext),
.read_probe = dhav_probe,
.read_header = dhav_read_header,
.read_packet = dhav_read_packet,
.read_seek = dhav_read_seek,
};
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