linux/drivers/media/v4l2-core/v4l2-jpeg.c
Mirela Rabulea 819f3ea51d media: Avoid parsing quantization and huffman tables
These are optional in struct v4l2_jpeg_header, so skip DHT/DQT segment
parsing if huffman_tables/quantization_tables were not requested by user,
to save time.
However, do count them (num_dht/num_dqt).

Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2021-03-22 10:40:13 +01:00

678 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* V4L2 JPEG header parser helpers.
*
* Copyright (C) 2019 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
*
* For reference, see JPEG ITU-T.81 (ISO/IEC 10918-1) [1]
*
* [1] https://www.w3.org/Graphics/JPEG/itu-t81.pdf
*/
#include <asm/unaligned.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <media/v4l2-jpeg.h>
MODULE_DESCRIPTION("V4L2 JPEG header parser helpers");
MODULE_AUTHOR("Philipp Zabel <kernel@pengutronix.de>");
MODULE_LICENSE("GPL");
/* Table B.1 - Marker code assignments */
#define SOF0 0xffc0 /* start of frame */
#define SOF1 0xffc1
#define SOF2 0xffc2
#define SOF3 0xffc3
#define SOF5 0xffc5
#define SOF7 0xffc7
#define JPG 0xffc8 /* extensions */
#define SOF9 0xffc9
#define SOF11 0xffcb
#define SOF13 0xffcd
#define SOF15 0xffcf
#define DHT 0xffc4 /* huffman table */
#define DAC 0xffcc /* arithmetic coding conditioning */
#define RST0 0xffd0 /* restart */
#define RST7 0xffd7
#define SOI 0xffd8 /* start of image */
#define EOI 0xffd9 /* end of image */
#define SOS 0xffda /* start of stream */
#define DQT 0xffdb /* quantization table */
#define DNL 0xffdc /* number of lines */
#define DRI 0xffdd /* restart interval */
#define DHP 0xffde /* hierarchical progression */
#define EXP 0xffdf /* expand reference */
#define APP0 0xffe0 /* application data */
#define APP14 0xffee /* application data for colour encoding */
#define APP15 0xffef
#define JPG0 0xfff0 /* extensions */
#define JPG13 0xfffd
#define COM 0xfffe /* comment */
#define TEM 0xff01 /* temporary */
/**
* struct jpeg_stream - JPEG byte stream
* @curr: current position in stream
* @end: end position, after last byte
*/
struct jpeg_stream {
u8 *curr;
u8 *end;
};
/* returns a value that fits into u8, or negative error */
static int jpeg_get_byte(struct jpeg_stream *stream)
{
if (stream->curr >= stream->end)
return -EINVAL;
return *stream->curr++;
}
/* returns a value that fits into u16, or negative error */
static int jpeg_get_word_be(struct jpeg_stream *stream)
{
u16 word;
if (stream->curr + sizeof(__be16) > stream->end)
return -EINVAL;
word = get_unaligned_be16(stream->curr);
stream->curr += sizeof(__be16);
return word;
}
static int jpeg_skip(struct jpeg_stream *stream, size_t len)
{
if (stream->curr + len > stream->end)
return -EINVAL;
stream->curr += len;
return 0;
}
static int jpeg_next_marker(struct jpeg_stream *stream)
{
int byte;
u16 marker = 0;
while ((byte = jpeg_get_byte(stream)) >= 0) {
marker = (marker << 8) | byte;
/* skip stuffing bytes and REServed markers */
if (marker == TEM || (marker > 0xffbf && marker < 0xffff))
return marker;
}
return byte;
}
/* this does not advance the current position in the stream */
static int jpeg_reference_segment(struct jpeg_stream *stream,
struct v4l2_jpeg_reference *segment)
{
u16 len;
if (stream->curr + sizeof(__be16) > stream->end)
return -EINVAL;
len = get_unaligned_be16(stream->curr);
if (stream->curr + len > stream->end)
return -EINVAL;
segment->start = stream->curr;
segment->length = len;
return 0;
}
static int v4l2_jpeg_decode_subsampling(u8 nf, u8 h_v)
{
if (nf == 1)
return V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY;
/* no chroma subsampling for 4-component images */
if (nf == 4 && h_v != 0x11)
return -EINVAL;
switch (h_v) {
case 0x11:
return V4L2_JPEG_CHROMA_SUBSAMPLING_444;
case 0x21:
return V4L2_JPEG_CHROMA_SUBSAMPLING_422;
case 0x22:
return V4L2_JPEG_CHROMA_SUBSAMPLING_420;
case 0x41:
return V4L2_JPEG_CHROMA_SUBSAMPLING_411;
default:
return -EINVAL;
}
}
static int jpeg_parse_frame_header(struct jpeg_stream *stream, u16 sof_marker,
struct v4l2_jpeg_frame_header *frame_header)
{
int len = jpeg_get_word_be(stream);
if (len < 0)
return len;
/* Lf = 8 + 3 * Nf, Nf >= 1 */
if (len < 8 + 3)
return -EINVAL;
if (frame_header) {
/* Table B.2 - Frame header parameter sizes and values */
int p, y, x, nf;
int i;
p = jpeg_get_byte(stream);
if (p < 0)
return p;
/*
* Baseline DCT only supports 8-bit precision.
* Extended sequential DCT also supports 12-bit precision.
*/
if (p != 8 && (p != 12 || sof_marker != SOF1))
return -EINVAL;
y = jpeg_get_word_be(stream);
if (y < 0)
return y;
if (y == 0)
return -EINVAL;
x = jpeg_get_word_be(stream);
if (x < 0)
return x;
if (x == 0)
return -EINVAL;
nf = jpeg_get_byte(stream);
if (nf < 0)
return nf;
/*
* The spec allows 1 <= Nf <= 255, but we only support up to 4
* components.
*/
if (nf < 1 || nf > V4L2_JPEG_MAX_COMPONENTS)
return -EINVAL;
if (len != 8 + 3 * nf)
return -EINVAL;
frame_header->precision = p;
frame_header->height = y;
frame_header->width = x;
frame_header->num_components = nf;
for (i = 0; i < nf; i++) {
struct v4l2_jpeg_frame_component_spec *component;
int c, h_v, tq;
c = jpeg_get_byte(stream);
if (c < 0)
return c;
h_v = jpeg_get_byte(stream);
if (h_v < 0)
return h_v;
if (i == 0) {
int subs;
subs = v4l2_jpeg_decode_subsampling(nf, h_v);
if (subs < 0)
return subs;
frame_header->subsampling = subs;
} else if (h_v != 0x11) {
/* all chroma sampling factors must be 1 */
return -EINVAL;
}
tq = jpeg_get_byte(stream);
if (tq < 0)
return tq;
component = &frame_header->component[i];
component->component_identifier = c;
component->horizontal_sampling_factor =
(h_v >> 4) & 0xf;
component->vertical_sampling_factor = h_v & 0xf;
component->quantization_table_selector = tq;
}
} else {
return jpeg_skip(stream, len - 2);
}
return 0;
}
static int jpeg_parse_scan_header(struct jpeg_stream *stream,
struct v4l2_jpeg_scan_header *scan_header)
{
size_t skip;
int len = jpeg_get_word_be(stream);
if (len < 0)
return len;
/* Ls = 8 + 3 * Ns, Ns >= 1 */
if (len < 6 + 2)
return -EINVAL;
if (scan_header) {
int ns;
int i;
ns = jpeg_get_byte(stream);
if (ns < 0)
return ns;
if (ns < 1 || ns > 4 || len != 6 + 2 * ns)
return -EINVAL;
scan_header->num_components = ns;
for (i = 0; i < ns; i++) {
struct v4l2_jpeg_scan_component_spec *component;
int cs, td_ta;
cs = jpeg_get_byte(stream);
if (cs < 0)
return cs;
td_ta = jpeg_get_byte(stream);
if (td_ta < 0)
return td_ta;
component = &scan_header->component[i];
component->component_selector = cs;
component->dc_entropy_coding_table_selector =
(td_ta >> 4) & 0xf;
component->ac_entropy_coding_table_selector =
td_ta & 0xf;
}
skip = 3; /* skip Ss, Se, Ah, and Al */
} else {
skip = len - 2;
}
return jpeg_skip(stream, skip);
}
/* B.2.4.1 Quantization table-specification syntax */
static int jpeg_parse_quantization_tables(struct jpeg_stream *stream,
u8 precision,
struct v4l2_jpeg_reference *tables)
{
int len = jpeg_get_word_be(stream);
if (len < 0)
return len;
/* Lq = 2 + n * 65 (for baseline DCT), n >= 1 */
if (len < 2 + 65)
return -EINVAL;
len -= 2;
while (len >= 65) {
u8 pq, tq, *qk;
int ret;
int pq_tq = jpeg_get_byte(stream);
if (pq_tq < 0)
return pq_tq;
/* quantization table element precision */
pq = (pq_tq >> 4) & 0xf;
/*
* Only 8-bit Qk values for 8-bit sample precision. Extended
* sequential DCT with 12-bit sample precision also supports
* 16-bit Qk values.
*/
if (pq != 0 && (pq != 1 || precision != 12))
return -EINVAL;
/* quantization table destination identifier */
tq = pq_tq & 0xf;
if (tq > 3)
return -EINVAL;
/* quantization table element */
qk = stream->curr;
ret = jpeg_skip(stream, pq ? 128 : 64);
if (ret < 0)
return -EINVAL;
if (tables) {
tables[tq].start = qk;
tables[tq].length = pq ? 128 : 64;
}
len -= pq ? 129 : 65;
}
return 0;
}
/* B.2.4.2 Huffman table-specification syntax */
static int jpeg_parse_huffman_tables(struct jpeg_stream *stream,
struct v4l2_jpeg_reference *tables)
{
int mt;
int len = jpeg_get_word_be(stream);
if (len < 0)
return len;
/* Table B.5 - Huffman table specification parameter sizes and values */
if (len < 2 + 17)
return -EINVAL;
for (len -= 2; len >= 17; len -= 17 + mt) {
u8 tc, th, *table;
int tc_th = jpeg_get_byte(stream);
int i, ret;
if (tc_th < 0)
return tc_th;
/* table class - 0 = DC, 1 = AC */
tc = (tc_th >> 4) & 0xf;
if (tc > 1)
return -EINVAL;
/* huffman table destination identifier */
th = tc_th & 0xf;
/* only two Huffman tables for baseline DCT */
if (th > 1)
return -EINVAL;
/* BITS - number of Huffman codes with length i */
table = stream->curr;
mt = 0;
for (i = 0; i < 16; i++) {
int li;
li = jpeg_get_byte(stream);
if (li < 0)
return li;
mt += li;
}
/* HUFFVAL - values associated with each Huffman code */
ret = jpeg_skip(stream, mt);
if (ret < 0)
return ret;
if (tables) {
tables[(tc << 1) | th].start = table;
tables[(tc << 1) | th].length = stream->curr - table;
}
}
return jpeg_skip(stream, len - 2);
}
/* B.2.4.4 Restart interval definition syntax */
static int jpeg_parse_restart_interval(struct jpeg_stream *stream,
u16 *restart_interval)
{
int len = jpeg_get_word_be(stream);
int ri;
if (len < 0)
return len;
if (len != 4)
return -EINVAL;
ri = jpeg_get_word_be(stream);
if (ri < 0)
return ri;
*restart_interval = ri;
return 0;
}
static int jpeg_skip_segment(struct jpeg_stream *stream)
{
int len = jpeg_get_word_be(stream);
if (len < 0)
return len;
if (len < 2)
return -EINVAL;
return jpeg_skip(stream, len - 2);
}
/* Rec. ITU-T T.872 (06/2012) 6.5.3 */
static int jpeg_parse_app14_data(struct jpeg_stream *stream,
enum v4l2_jpeg_app14_tf *tf)
{
int ret;
int lp;
int skip;
lp = jpeg_get_word_be(stream);
if (lp < 0)
return lp;
/* Check for "Adobe\0" in Ap1..6 */
if (stream->curr + 6 > stream->end ||
strncmp(stream->curr, "Adobe\0", 6))
return -EINVAL;
/* get to Ap12 */
ret = jpeg_skip(stream, 11);
if (ret < 0)
return ret;
ret = jpeg_get_byte(stream);
if (ret < 0)
return ret;
*tf = ret;
/* skip the rest of the segment, this ensures at least it is complete */
skip = lp - 2 - 11;
return jpeg_skip(stream, skip);
}
/**
* v4l2_jpeg_parse_header - locate marker segments and optionally parse headers
* @buf: address of the JPEG buffer, should start with a SOI marker
* @len: length of the JPEG buffer
* @out: returns marker segment positions and optionally parsed headers
*
* The out->scan_header pointer must be initialized to NULL or point to a valid
* v4l2_jpeg_scan_header structure. The out->huffman_tables and
* out->quantization_tables pointers must be initialized to NULL or point to a
* valid array of 4 v4l2_jpeg_reference structures each.
*
* Returns 0 or negative error if parsing failed.
*/
int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out)
{
struct jpeg_stream stream;
int marker;
int ret = 0;
stream.curr = buf;
stream.end = stream.curr + len;
out->num_dht = 0;
out->num_dqt = 0;
/* the first bytes must be SOI, B.2.1 High-level syntax */
if (jpeg_get_word_be(&stream) != SOI)
return -EINVAL;
/* init value to signal if this marker is not present */
out->app14_tf = V4L2_JPEG_APP14_TF_UNKNOWN;
/* loop through marker segments */
while ((marker = jpeg_next_marker(&stream)) >= 0) {
switch (marker) {
/* baseline DCT, extended sequential DCT */
case SOF0 ... SOF1:
ret = jpeg_reference_segment(&stream, &out->sof);
if (ret < 0)
return ret;
ret = jpeg_parse_frame_header(&stream, marker,
&out->frame);
break;
/* progressive, lossless */
case SOF2 ... SOF3:
/* differential coding */
case SOF5 ... SOF7:
/* arithmetic coding */
case SOF9 ... SOF11:
case SOF13 ... SOF15:
case DAC:
case TEM:
return -EINVAL;
case DHT:
ret = jpeg_reference_segment(&stream,
&out->dht[out->num_dht++ % 4]);
if (ret < 0)
return ret;
if (!out->huffman_tables) {
ret = jpeg_skip_segment(&stream);
break;
}
ret = jpeg_parse_huffman_tables(&stream,
out->huffman_tables);
break;
case DQT:
ret = jpeg_reference_segment(&stream,
&out->dqt[out->num_dqt++ % 4]);
if (ret < 0)
return ret;
if (!out->quantization_tables) {
ret = jpeg_skip_segment(&stream);
break;
}
ret = jpeg_parse_quantization_tables(&stream,
out->frame.precision,
out->quantization_tables);
break;
case DRI:
ret = jpeg_parse_restart_interval(&stream,
&out->restart_interval);
break;
case APP14:
ret = jpeg_parse_app14_data(&stream,
&out->app14_tf);
break;
case SOS:
ret = jpeg_reference_segment(&stream, &out->sos);
if (ret < 0)
return ret;
ret = jpeg_parse_scan_header(&stream, out->scan);
/*
* stop parsing, the scan header marks the beginning of
* the entropy coded segment
*/
out->ecs_offset = stream.curr - (u8 *)buf;
return ret;
/* markers without parameters */
case RST0 ... RST7: /* restart */
case SOI: /* start of image */
case EOI: /* end of image */
break;
/* skip unknown or unsupported marker segments */
default:
ret = jpeg_skip_segment(&stream);
break;
}
if (ret < 0)
return ret;
}
return marker;
}
EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_header);
/**
* v4l2_jpeg_parse_frame_header - parse frame header
* @buf: address of the frame header, after the SOF0 marker
* @len: length of the frame header
* @frame_header: returns the parsed frame header
*
* Returns 0 or negative error if parsing failed.
*/
int v4l2_jpeg_parse_frame_header(void *buf, size_t len,
struct v4l2_jpeg_frame_header *frame_header)
{
struct jpeg_stream stream;
stream.curr = buf;
stream.end = stream.curr + len;
return jpeg_parse_frame_header(&stream, SOF0, frame_header);
}
EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_frame_header);
/**
* v4l2_jpeg_parse_scan_header - parse scan header
* @buf: address of the scan header, after the SOS marker
* @len: length of the scan header
* @scan_header: returns the parsed scan header
*
* Returns 0 or negative error if parsing failed.
*/
int v4l2_jpeg_parse_scan_header(void *buf, size_t len,
struct v4l2_jpeg_scan_header *scan_header)
{
struct jpeg_stream stream;
stream.curr = buf;
stream.end = stream.curr + len;
return jpeg_parse_scan_header(&stream, scan_header);
}
EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_scan_header);
/**
* v4l2_jpeg_parse_quantization_tables - parse quantization tables segment
* @buf: address of the quantization table segment, after the DQT marker
* @len: length of the quantization table segment
* @precision: sample precision (P) in bits per component
* @q_tables: returns four references into the buffer for the
* four possible quantization table destinations
*
* Returns 0 or negative error if parsing failed.
*/
int v4l2_jpeg_parse_quantization_tables(void *buf, size_t len, u8 precision,
struct v4l2_jpeg_reference *q_tables)
{
struct jpeg_stream stream;
stream.curr = buf;
stream.end = stream.curr + len;
return jpeg_parse_quantization_tables(&stream, precision, q_tables);
}
EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_quantization_tables);
/**
* v4l2_jpeg_parse_huffman_tables - parse huffman tables segment
* @buf: address of the Huffman table segment, after the DHT marker
* @len: length of the Huffman table segment
* @huffman_tables: returns four references into the buffer for the
* four possible Huffman table destinations, in
* the order DC0, DC1, AC0, AC1
*
* Returns 0 or negative error if parsing failed.
*/
int v4l2_jpeg_parse_huffman_tables(void *buf, size_t len,
struct v4l2_jpeg_reference *huffman_tables)
{
struct jpeg_stream stream;
stream.curr = buf;
stream.end = stream.curr + len;
return jpeg_parse_huffman_tables(&stream, huffman_tables);
}
EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_huffman_tables);