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lavf/rtpenc_jpeg: Less strict check for standard Huffman tables.

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There can be one or more Huffman table segments DHT.

Reported-by: Andrey Utkin
This commit is contained in:
Carl Eugen Hoyos 2015-12-02 14:56:53 +01:00
parent ff3e717003
commit aa3101a9e8
1 changed files with 66 additions and 17 deletions
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83
libavformat/rtpenc_jpeg.c
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@ -36,6 +36,7 @@ void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
int off = 0; /* fragment offset of the current JPEG frame */
int len;
int i;
int default_huffman_tables = 0;
s->buf_ptr = s->buf;
s->timestamp = s->cur_timestamp;
@ -90,23 +91,66 @@ void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
return;
}
} else if (buf[i + 1] == DHT) {
if ( AV_RB16(&buf[i + 2]) < 418
|| i + 420 >= size
|| buf[i + 4] != 0x00
|| buf[i + 33] != 0x01
|| buf[i + 62] != 0x10
|| buf[i + 241] != 0x11
|| memcmp(buf + i + 5, avpriv_mjpeg_bits_dc_luminance + 1, 16)
|| memcmp(buf + i + 21, avpriv_mjpeg_val_dc, 12)
|| memcmp(buf + i + 34, avpriv_mjpeg_bits_dc_chrominance + 1, 16)
|| memcmp(buf + i + 50, avpriv_mjpeg_val_dc, 12)
|| memcmp(buf + i + 63, avpriv_mjpeg_bits_ac_luminance + 1, 16)
|| memcmp(buf + i + 79, avpriv_mjpeg_val_ac_luminance, 162)
|| memcmp(buf + i + 242, avpriv_mjpeg_bits_ac_chrominance + 1, 16)
|| memcmp(buf + i + 258, avpriv_mjpeg_val_ac_chrominance, 162)) {
av_log(s1, AV_LOG_ERROR,
"RFC 2435 requires standard Huffman tables for jpeg\n");
return;
int dht_size = AV_RB16(&buf[i + 2]);
default_huffman_tables |= 1 << 4;
i += 3;
dht_size -= 2;
if (i + dht_size >= size)
continue;
while (dht_size > 0)
switch (buf[i + 1]) {
case 0x00:
if ( dht_size >= 29
&& !memcmp(buf + i + 2, avpriv_mjpeg_bits_dc_luminance + 1, 16)
&& !memcmp(buf + i + 18, avpriv_mjpeg_val_dc, 12)) {
default_huffman_tables |= 1;
i += 29;
dht_size -= 29;
} else {
i += dht_size;
dht_size = 0;
}
break;
case 0x01:
if ( dht_size >= 29
&& !memcmp(buf + i + 2, avpriv_mjpeg_bits_dc_chrominance + 1, 16)
&& !memcmp(buf + i + 18, avpriv_mjpeg_val_dc, 12)) {
default_huffman_tables |= 1 << 1;
i += 29;
dht_size -= 29;
} else {
i += dht_size;
dht_size = 0;
}
break;
case 0x10:
if ( dht_size >= 179
&& !memcmp(buf + i + 2, avpriv_mjpeg_bits_ac_luminance + 1, 16)
&& !memcmp(buf + i + 18, avpriv_mjpeg_val_ac_luminance, 162)) {
default_huffman_tables |= 1 << 2;
i += 179;
dht_size -= 179;
} else {
i += dht_size;
dht_size = 0;
}
break;
case 0x11:
if ( dht_size >= 179
&& !memcmp(buf + i + 2, avpriv_mjpeg_bits_ac_chrominance + 1, 16)
&& !memcmp(buf + i + 18, avpriv_mjpeg_val_ac_chrominance, 162)) {
default_huffman_tables |= 1 << 3;
i += 179;
dht_size -= 179;
} else {
i += dht_size;
dht_size = 0;
}
break;
default:
i += dht_size;
dht_size = 0;
continue;
}
} else if (buf[i + 1] == SOS) {
/* SOS is last marker in the header */
@ -119,6 +163,11 @@ void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
break;
}
}
if (default_huffman_tables && default_huffman_tables != 31) {
av_log(s1, AV_LOG_ERROR,
"RFC 2435 requires standard Huffman tables for jpeg\n");
return;
}
if (nb_qtables && nb_qtables != 2)
av_log(s1, AV_LOG_WARNING,
"RFC 2435 suggests two quantization tables, %d provided\n",