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FFmpeg/libavcodec/cbs_jpeg.c
Andreas Rheinhardt 14dd0a9057 avcodec/cbs: Avoid leaving the ... out in calls to variadic macros 
According to C99, there has to be at least one argument for every ...
in a variadic function-like macro. In practice most (all?) compilers also
allow to leave it completely out, but it is nevertheless required: In a
variadic macro "there shall be more arguments in the invocation than there
are parameters in the macro definition (excluding the ...)." (C99,
6.10.3.4).

CBS (not the framework itself, but the macros used in the
cbs_*_syntax_template.c files) relies on the compiler allowing to leave
a variadic macro argument out. This leads to warnings when compiling in
-pedantic mode, e.g. "warning: must specify at least one argument for
'...' parameter of variadic macro [-Wgnu-zero-variadic-macro-arguments]"
from Clang.

Most of these warnings can be easily avoided: The syntax_templates
mostly contain helper macros that expand to more complex variadic macros
and these helper macros often omit an argument for the .... Modifying
them to always expand to complex macros with an empty argument for the
... at the end fixes most of these warnings: The number of warnings went
down from 400 to 0 for cbs_av1, from 1114 to 32 for cbs_h2645, from 38 to
0 for cbs_jpeg, from 166 to 0 for cbs_mpeg2 and from 110 to 8 for cbs_vp9.

These eight remaining warnings for cbs_vp9 have been fixed by switching
to another macro in cbs_vp9_syntax_template: The fixed values for the
sync bytes as well as the trailing bits for byte-alignment are now read
via the fixed() macro (this also adds a check to ensure that trailing
bits are indeed zero as they have to be).

Reviewed-by: Mark Thompson <sw@jkqxz.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-04-12 23:23:49 +02:00

469 lines
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/*
* 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 "cbs.h"
#include "cbs_internal.h"
#include "cbs_jpeg.h"
#define HEADER(name) do { \
ff_cbs_trace_header(ctx, name); \
} while (0)
#define CHECK(call) do { \
err = (call); \
if (err < 0) \
return err; \
} while (0)
#define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL)
#define u(width, name, range_min, range_max) \
xu(width, name, range_min, range_max, 0, )
#define us(width, name, sub, range_min, range_max) \
xu(width, name, range_min, range_max, 1, sub)
#define READ
#define READWRITE read
#define RWContext GetBitContext
#define FUNC(name) cbs_jpeg_read_ ## name
#define xu(width, name, range_min, range_max, subs, ...) do { \
uint32_t value; \
CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
SUBSCRIPTS(subs, __VA_ARGS__), \
&value, range_min, range_max)); \
current->name = value; \
} while (0)
#include "cbs_jpeg_syntax_template.c"
#undef READ
#undef READWRITE
#undef RWContext
#undef FUNC
#undef xu
#define WRITE
#define READWRITE write
#define RWContext PutBitContext
#define FUNC(name) cbs_jpeg_write_ ## name
#define xu(width, name, range_min, range_max, subs, ...) do { \
uint32_t value = current->name; \
CHECK(ff_cbs_write_unsigned(ctx, rw, width, #name, \
SUBSCRIPTS(subs, __VA_ARGS__), \
value, range_min, range_max)); \
} while (0)
#include "cbs_jpeg_syntax_template.c"
#undef WRITE
#undef READWRITE
#undef RWContext
#undef FUNC
#undef xu
static void cbs_jpeg_free_application_data(void *opaque, uint8_t *content)
{
JPEGRawApplicationData *ad = (JPEGRawApplicationData*)content;
av_buffer_unref(&ad->Ap_ref);
av_freep(&content);
}
static void cbs_jpeg_free_comment(void *opaque, uint8_t *content)
{
JPEGRawComment *comment = (JPEGRawComment*)content;
av_buffer_unref(&comment->Cm_ref);
av_freep(&content);
}
static void cbs_jpeg_free_scan(void *opaque, uint8_t *content)
{
JPEGRawScan *scan = (JPEGRawScan*)content;
av_buffer_unref(&scan->data_ref);
av_freep(&content);
}
static int cbs_jpeg_split_fragment(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag,
int header)
{
AVBufferRef *data_ref;
uint8_t *data;
size_t data_size;
int unit, start, end, marker, next_start, next_marker;
int err, i, j, length;
if (frag->data_size < 4) {
// Definitely too short to be meaningful.
return AVERROR_INVALIDDATA;
}
for (i = 0; i + 1 < frag->data_size && frag->data[i] != 0xff; i++);
if (i > 0) {
av_log(ctx->log_ctx, AV_LOG_WARNING, "Discarding %d bytes at "
"beginning of image.\n", i);
}
for (++i; i + 1 < frag->data_size && frag->data[i] == 0xff; i++);
if (i + 1 >= frag->data_size && frag->data[i]) {
av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
"no SOI marker found.\n");
return AVERROR_INVALIDDATA;
}
marker = frag->data[i];
if (marker != JPEG_MARKER_SOI) {
av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: first "
"marker is %02x, should be SOI.\n", marker);
return AVERROR_INVALIDDATA;
}
for (++i; i + 1 < frag->data_size && frag->data[i] == 0xff; i++);
if (i + 1 >= frag->data_size) {
av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
"no image content found.\n");
return AVERROR_INVALIDDATA;
}
marker = frag->data[i];
start = i + 1;
for (unit = 0;; unit++) {
if (marker == JPEG_MARKER_EOI) {
break;
} else if (marker == JPEG_MARKER_SOS) {
for (i = start; i + 1 < frag->data_size; i++) {
if (frag->data[i] != 0xff)
continue;
end = i;
for (++i; i + 1 < frag->data_size &&
frag->data[i] == 0xff; i++);
if (i + 1 >= frag->data_size) {
next_marker = -1;
} else {
if (frag->data[i] == 0x00)
continue;
next_marker = frag->data[i];
next_start = i + 1;
}
break;
}
} else {
i = start;
if (i + 2 > frag->data_size) {
av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
"truncated at %02x marker.\n", marker);
return AVERROR_INVALIDDATA;
}
length = AV_RB16(frag->data + i);
if (i + length > frag->data_size) {
av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
"truncated at %02x marker segment.\n", marker);
return AVERROR_INVALIDDATA;
}
end = start + length;
i = end;
if (frag->data[i] != 0xff) {
next_marker = -1;
} else {
for (++i; i + 1 < frag->data_size &&
frag->data[i] == 0xff; i++);
if (i + 1 >= frag->data_size) {
next_marker = -1;
} else {
next_marker = frag->data[i];
next_start = i + 1;
}
}
}
if (marker == JPEG_MARKER_SOS) {
length = AV_RB16(frag->data + start);
if (length > end - start)
return AVERROR_INVALIDDATA;
data_ref = NULL;
data = av_malloc(end - start +
AV_INPUT_BUFFER_PADDING_SIZE);
if (!data)
return AVERROR(ENOMEM);
memcpy(data, frag->data + start, length);
for (i = start + length, j = length; i < end; i++, j++) {
if (frag->data[i] == 0xff) {
while (frag->data[i] == 0xff)
++i;
data[j] = 0xff;
} else {
data[j] = frag->data[i];
}
}
data_size = j;
memset(data + data_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
} else {
data = frag->data + start;
data_size = end - start;
data_ref = frag->data_ref;
}
err = ff_cbs_insert_unit_data(ctx, frag, unit, marker,
data, data_size, data_ref);
if (err < 0)
return err;
if (next_marker == -1)
break;
marker = next_marker;
start = next_start;
}
return 0;
}
static int cbs_jpeg_read_unit(CodedBitstreamContext *ctx,
CodedBitstreamUnit *unit)
{
GetBitContext gbc;
int err;
err = init_get_bits(&gbc, unit->data, 8 * unit->data_size);
if (err < 0)
return err;
if (unit->type >= JPEG_MARKER_SOF0 &&
unit->type <= JPEG_MARKER_SOF3) {
err = ff_cbs_alloc_unit_content(ctx, unit,
sizeof(JPEGRawFrameHeader),
NULL);
if (err < 0)
return err;
err = cbs_jpeg_read_frame_header(ctx, &gbc, unit->content);
if (err < 0)
return err;
} else if (unit->type >= JPEG_MARKER_APPN &&
unit->type <= JPEG_MARKER_APPN + 15) {
err = ff_cbs_alloc_unit_content(ctx, unit,
sizeof(JPEGRawApplicationData),
&cbs_jpeg_free_application_data);
if (err < 0)
return err;
err = cbs_jpeg_read_application_data(ctx, &gbc, unit->content);
if (err < 0)
return err;
} else if (unit->type == JPEG_MARKER_SOS) {
JPEGRawScan *scan;
int pos;
err = ff_cbs_alloc_unit_content(ctx, unit,
sizeof(JPEGRawScan),
&cbs_jpeg_free_scan);
if (err < 0)
return err;
scan = unit->content;
err = cbs_jpeg_read_scan_header(ctx, &gbc, &scan->header);
if (err < 0)
return err;
pos = get_bits_count(&gbc);
av_assert0(pos % 8 == 0);
if (pos > 0) {
scan->data_size = unit->data_size - pos / 8;
scan->data_ref = av_buffer_ref(unit->data_ref);
if (!scan->data_ref)
return AVERROR(ENOMEM);
scan->data = unit->data + pos / 8;
}
} else {
switch (unit->type) {
#define SEGMENT(marker, type, func, free) \
case JPEG_MARKER_ ## marker: \
{ \
err = ff_cbs_alloc_unit_content(ctx, unit, \
sizeof(type), free); \
if (err < 0) \
return err; \
err = cbs_jpeg_read_ ## func(ctx, &gbc, unit->content); \
if (err < 0) \
return err; \
} \
break
SEGMENT(DQT, JPEGRawQuantisationTableSpecification, dqt, NULL);
SEGMENT(DHT, JPEGRawHuffmanTableSpecification, dht, NULL);
SEGMENT(COM, JPEGRawComment, comment, &cbs_jpeg_free_comment);
#undef SEGMENT
default:
return AVERROR(ENOSYS);
}
}
return 0;
}
static int cbs_jpeg_write_scan(CodedBitstreamContext *ctx,
CodedBitstreamUnit *unit,
PutBitContext *pbc)
{
JPEGRawScan *scan = unit->content;
int err;
err = cbs_jpeg_write_scan_header(ctx, pbc, &scan->header);
if (err < 0)
return err;
if (scan->data) {
if (scan->data_size * 8 > put_bits_left(pbc))
return AVERROR(ENOSPC);
av_assert0(put_bits_count(pbc) % 8 == 0);
flush_put_bits(pbc);
memcpy(put_bits_ptr(pbc), scan->data, scan->data_size);
skip_put_bytes(pbc, scan->data_size);
}
return 0;
}
static int cbs_jpeg_write_segment(CodedBitstreamContext *ctx,
CodedBitstreamUnit *unit,
PutBitContext *pbc)
{
int err;
if (unit->type >= JPEG_MARKER_SOF0 &&
unit->type <= JPEG_MARKER_SOF3) {
err = cbs_jpeg_write_frame_header(ctx, pbc, unit->content);
} else if (unit->type >= JPEG_MARKER_APPN &&
unit->type <= JPEG_MARKER_APPN + 15) {
err = cbs_jpeg_write_application_data(ctx, pbc, unit->content);
} else {
switch (unit->type) {
#define SEGMENT(marker, func) \
case JPEG_MARKER_ ## marker: \
err = cbs_jpeg_write_ ## func(ctx, pbc, unit->content); \
break;
SEGMENT(DQT, dqt);
SEGMENT(DHT, dht);
SEGMENT(COM, comment);
default:
return AVERROR_PATCHWELCOME;
}
}
return err;
}
static int cbs_jpeg_write_unit(CodedBitstreamContext *ctx,
CodedBitstreamUnit *unit,
PutBitContext *pbc)
{
if (unit->type == JPEG_MARKER_SOS)
return cbs_jpeg_write_scan (ctx, unit, pbc);
else
return cbs_jpeg_write_segment(ctx, unit, pbc);
}
static int cbs_jpeg_assemble_fragment(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag)
{
const CodedBitstreamUnit *unit;
uint8_t *data;
size_t size, dp, sp;
int i;
size = 4; // SOI + EOI.
for (i = 0; i < frag->nb_units; i++) {
unit = &frag->units[i];
size += 2 + unit->data_size;
if (unit->type == JPEG_MARKER_SOS) {
for (sp = 0; sp < unit->data_size; sp++) {
if (unit->data[sp] == 0xff)
++size;
}
}
}
frag->data_ref = av_buffer_alloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!frag->data_ref)
return AVERROR(ENOMEM);
data = frag->data_ref->data;
dp = 0;
data[dp++] = 0xff;
data[dp++] = JPEG_MARKER_SOI;
for (i = 0; i < frag->nb_units; i++) {
unit = &frag->units[i];
data[dp++] = 0xff;
data[dp++] = unit->type;
if (unit->type != JPEG_MARKER_SOS) {
memcpy(data + dp, unit->data, unit->data_size);
dp += unit->data_size;
} else {
sp = AV_RB16(unit->data);
av_assert0(sp <= unit->data_size);
memcpy(data + dp, unit->data, sp);
dp += sp;
for (; sp < unit->data_size; sp++) {
if (unit->data[sp] == 0xff) {
data[dp++] = 0xff;
data[dp++] = 0x00;
} else {
data[dp++] = unit->data[sp];
}
}
}
}
data[dp++] = 0xff;
data[dp++] = JPEG_MARKER_EOI;
av_assert0(dp == size);
memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
frag->data = data;
frag->data_size = size;
return 0;
}
const CodedBitstreamType ff_cbs_type_jpeg = {
.codec_id = AV_CODEC_ID_MJPEG,
.split_fragment = &cbs_jpeg_split_fragment,
.read_unit = &cbs_jpeg_read_unit,
.write_unit = &cbs_jpeg_write_unit,
.assemble_fragment = &cbs_jpeg_assemble_fragment,
};
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