avcodec/g2meet, mjpegdec: Factor out common VLC initialization code

While just at it, remove the nb_codes parameter: It is redundant
(the number of codes is implicitly contained in the array containing how
many entries of a specific size there are) and for this reason it might
even be wrong, so it is better to check what is actually used instead.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2021-02-10 00:20:26 +01:00
parent f180f515de
commit d26198ada3
5 changed files with 77 additions and 72 deletions

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@ -342,7 +342,7 @@ OBJS-$(CONFIG_FMVC_DECODER) += fmvc.o
OBJS-$(CONFIG_FOURXM_DECODER) += 4xm.o
OBJS-$(CONFIG_FRAPS_DECODER) += fraps.o
OBJS-$(CONFIG_FRWU_DECODER) += frwu.o
OBJS-$(CONFIG_G2M_DECODER) += g2meet.o elsdec.o
OBJS-$(CONFIG_G2M_DECODER) += g2meet.o elsdec.o mjpegdec_common.o
OBJS-$(CONFIG_G723_1_DECODER) += g723_1dec.o g723_1.o \
acelp_vectors.o celp_filters.o celp_math.o
OBJS-$(CONFIG_G723_1_ENCODER) += g723_1enc.o g723_1.o \
@ -451,7 +451,7 @@ OBJS-$(CONFIG_METASOUND_DECODER) += metasound.o metasound_data.o \
twinvq.o
OBJS-$(CONFIG_MICRODVD_DECODER) += microdvddec.o ass.o
OBJS-$(CONFIG_MIMIC_DECODER) += mimic.o
OBJS-$(CONFIG_MJPEG_DECODER) += mjpegdec.o
OBJS-$(CONFIG_MJPEG_DECODER) += mjpegdec.o mjpegdec_common.o
OBJS-$(CONFIG_MJPEG_QSV_DECODER) += qsvdec.o
OBJS-$(CONFIG_MJPEG_ENCODER) += mjpegenc.o mjpegenc_common.o \
mjpegenc_huffman.o

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@ -41,6 +41,7 @@
#include "internal.h"
#include "jpegtables.h"
#include "mjpeg.h"
#include "mjpegdec.h"
#define EPIC_PIX_STACK_SIZE 1024
#define EPIC_PIX_STACK_MAX (EPIC_PIX_STACK_SIZE - 1)
@ -159,45 +160,24 @@ typedef struct G2MContext {
int cursor_hot_x, cursor_hot_y;
} G2MContext;
static av_cold int build_vlc(VLC *vlc, const uint8_t *bits_table,
const uint8_t *val_table, int nb_codes,
int is_ac)
{
uint8_t huff_size[256] = { 0 };
uint16_t huff_code[256];
uint16_t huff_sym[256];
int i;
ff_mjpeg_build_huffman_codes(huff_size, huff_code, bits_table, val_table);
for (i = 0; i < 256; i++)
huff_sym[i] = i + 16 * is_ac;
if (is_ac)
huff_sym[0] = 16 * 256;
return ff_init_vlc_sparse(vlc, 9, nb_codes, huff_size, 1, 1,
huff_code, 2, 2, huff_sym, 2, 2, 0);
}
static av_cold int jpg_init(AVCodecContext *avctx, JPGContext *c)
{
int ret;
ret = build_vlc(&c->dc_vlc[0], avpriv_mjpeg_bits_dc_luminance,
avpriv_mjpeg_val_dc, 12, 0);
ret = ff_mjpeg_build_vlc(&c->dc_vlc[0], avpriv_mjpeg_bits_dc_luminance,
avpriv_mjpeg_val_dc, 0, avctx);
if (ret)
return ret;
ret = build_vlc(&c->dc_vlc[1], avpriv_mjpeg_bits_dc_chrominance,
avpriv_mjpeg_val_dc, 12, 0);
ret = ff_mjpeg_build_vlc(&c->dc_vlc[1], avpriv_mjpeg_bits_dc_chrominance,
avpriv_mjpeg_val_dc, 0, avctx);
if (ret)
return ret;
ret = build_vlc(&c->ac_vlc[0], avpriv_mjpeg_bits_ac_luminance,
avpriv_mjpeg_val_ac_luminance, 251, 1);
ret = ff_mjpeg_build_vlc(&c->ac_vlc[0], avpriv_mjpeg_bits_ac_luminance,
avpriv_mjpeg_val_ac_luminance, 1, avctx);
if (ret)
return ret;
ret = build_vlc(&c->ac_vlc[1], avpriv_mjpeg_bits_ac_chrominance,
avpriv_mjpeg_val_ac_chrominance, 251, 1);
ret = ff_mjpeg_build_vlc(&c->ac_vlc[1], avpriv_mjpeg_bits_ac_chrominance,
avpriv_mjpeg_val_ac_chrominance, 1, avctx);
if (ret)
return ret;

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@ -51,40 +51,6 @@
#include "bytestream.h"
static void build_huffman_codes(uint8_t *huff_size, const uint8_t *bits_table)
{
for (int i = 1, k = 0; i <= 16; i++) {
int nb = bits_table[i];
for (int j = 0; j < nb;j++) {
huff_size[k] = i;
k++;
}
}
}
static int build_vlc(VLC *vlc, const uint8_t *bits_table,
const uint8_t *val_table, int nb_codes,
int is_ac, void *logctx)
{
uint8_t huff_size[256];
uint16_t huff_sym[256];
int i;
av_assert0(nb_codes <= 256);
build_huffman_codes(huff_size, bits_table);
for (i = 0; i < nb_codes; i++) {
huff_sym[i] = val_table[i] + 16 * is_ac;
if (is_ac && !val_table[i])
huff_sym[i] = 16 * 256;
}
return ff_init_vlc_from_lengths(vlc, 9, nb_codes, huff_size, 1,
huff_sym, 2, 2, 0, 0, logctx);
}
static int init_default_huffman_tables(MJpegDecodeContext *s)
{
static const struct {
@ -110,9 +76,9 @@ static int init_default_huffman_tables(MJpegDecodeContext *s)
int i, ret;
for (i = 0; i < FF_ARRAY_ELEMS(ht); i++) {
ret = build_vlc(&s->vlcs[ht[i].class][ht[i].index],
ht[i].bits, ht[i].values, ht[i].length,
ht[i].class == 1, s->avctx);
ret = ff_mjpeg_build_vlc(&s->vlcs[ht[i].class][ht[i].index],
ht[i].bits, ht[i].values,
ht[i].class == 1, s->avctx);
if (ret < 0)
return ret;
@ -307,14 +273,14 @@ int ff_mjpeg_decode_dht(MJpegDecodeContext *s)
ff_free_vlc(&s->vlcs[class][index]);
av_log(s->avctx, AV_LOG_DEBUG, "class=%d index=%d nb_codes=%d\n",
class, index, n);
if ((ret = build_vlc(&s->vlcs[class][index], bits_table, val_table,
n, class > 0, s->avctx)) < 0)
if ((ret = ff_mjpeg_build_vlc(&s->vlcs[class][index], bits_table,
val_table, class > 0, s->avctx)) < 0)
return ret;
if (class > 0) {
ff_free_vlc(&s->vlcs[2][index]);
if ((ret = build_vlc(&s->vlcs[2][index], bits_table, val_table,
n, 0, s->avctx)) < 0)
if ((ret = ff_mjpeg_build_vlc(&s->vlcs[2][index], bits_table,
val_table, 0, s->avctx)) < 0)
return ret;
}

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@ -161,6 +161,8 @@ typedef struct MJpegDecodeContext {
void *hwaccel_picture_private;
} MJpegDecodeContext;
int ff_mjpeg_build_vlc(VLC *vlc, const uint8_t *bits_table,
const uint8_t *val_table, int is_ac, void *logctx);
int ff_mjpeg_decode_init(AVCodecContext *avctx);
int ff_mjpeg_decode_end(AVCodecContext *avctx);
int ff_mjpeg_receive_frame(AVCodecContext *avctx, AVFrame *frame);

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@ -0,0 +1,57 @@
/*
* MJPEG decoder VLC code
* Copyright (c) 2000, 2001 Fabrice Bellard
* Copyright (c) 2003 Alex Beregszaszi
* Copyright (c) 2003-2004 Michael Niedermayer
*
* 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 <stdint.h>
#include "libavutil/avassert.h"
#include "mjpegdec.h"
#include "vlc.h"
static int build_huffman_codes(uint8_t *huff_size, const uint8_t *bits_table)
{
int nb_codes = 0;
for (int i = 1, j = 0; i <= 16; i++) {
nb_codes += bits_table[i];
av_assert1(nb_codes <= 256);
for (; j < nb_codes; j++)
huff_size[j] = i;
}
return nb_codes;
}
int ff_mjpeg_build_vlc(VLC *vlc, const uint8_t *bits_table,
const uint8_t *val_table, int is_ac, void *logctx)
{
uint8_t huff_size[256];
uint16_t huff_sym[256];
int nb_codes = build_huffman_codes(huff_size, bits_table);
for (int i = 0; i < nb_codes; i++) {
huff_sym[i] = val_table[i] + 16 * is_ac;
if (is_ac && !val_table[i])
huff_sym[i] = 16 * 256;
}
return ff_init_vlc_from_lengths(vlc, 9, nb_codes, huff_size, 1,
huff_sym, 2, 2, 0, 0, logctx);
}