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FFmpeg/libavcodec/cljrenc.c
Andreas Rheinhardt 5b8c18495c avcodec/cljrenc: Don't use too big buffers, don't copy them, set CAP_DR1
Up until now, the cljr encoder used buffers that were too big by a
factor of eight (probably bit/byte confusion). This has been fixed.
And because the needed buffer size can be easily calculated in advance,
one can avoid the implicit use of an intermediate buffer and can even
allow user-supplied buffers.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2021-05-05 12:35:55 +02:00

125 lines
4.2 KiB
C

/*
* Cirrus Logic AccuPak (CLJR) encoder
* Copyright (c) 2003 Alex Beregszaszi
*
* 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
*/
/**
* @file
* Cirrus Logic AccuPak encoder.
*/
#include "libavutil/common.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "encode.h"
#include "internal.h"
#include "put_bits.h"
typedef struct CLJRContext {
AVClass *avclass;
int dither_type;
} CLJRContext;
static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *p, int *got_packet)
{
CLJRContext *a = avctx->priv_data;
PutBitContext pb;
int x, y, ret;
uint32_t dither= avctx->frame_number;
static const uint32_t ordered_dither[2][2] =
{
{ 0x10400000, 0x104F0000 },
{ 0xCB2A0000, 0xCB250000 },
};
if (avctx->width%4 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
av_log(avctx, AV_LOG_ERROR,
"Widths which are not a multiple of 4 might fail with some decoders, "
"use vstrict=-1 / -strict -1 to use %d anyway.\n", avctx->width);
return AVERROR_EXPERIMENTAL;
}
ret = ff_get_encode_buffer(avctx, pkt, 4 * avctx->height * ((avctx->width + 3) / 4), 0);
if (ret < 0)
return ret;
init_put_bits(&pb, pkt->data, pkt->size);
for (y = 0; y < avctx->height; y++) {
uint8_t *luma = &p->data[0][y * p->linesize[0]];
uint8_t *cb = &p->data[1][y * p->linesize[1]];
uint8_t *cr = &p->data[2][y * p->linesize[2]];
uint8_t luma_tmp[4];
for (x = 0; x < avctx->width; x += 4) {
switch (a->dither_type) {
case 0: dither = 0x492A0000; break;
case 1: dither = dither * 1664525 + 1013904223; break;
case 2: dither = ordered_dither[ y&1 ][ (x>>2)&1 ];break;
}
if (x+3 >= avctx->width) {
memset(luma_tmp, 0, sizeof(luma_tmp));
memcpy(luma_tmp, luma, avctx->width - x);
luma = luma_tmp;
}
put_bits(&pb, 5, (249*(luma[3] + (dither>>29) )) >> 11);
put_bits(&pb, 5, (249*(luma[2] + ((dither>>26)&7))) >> 11);
put_bits(&pb, 5, (249*(luma[1] + ((dither>>23)&7))) >> 11);
put_bits(&pb, 5, (249*(luma[0] + ((dither>>20)&7))) >> 11);
luma += 4;
put_bits(&pb, 6, (253*(*(cb++) + ((dither>>18)&3))) >> 10);
put_bits(&pb, 6, (253*(*(cr++) + ((dither>>16)&3))) >> 10);
}
}
flush_put_bits(&pb);
pkt->flags |= AV_PKT_FLAG_KEY;
*got_packet = 1;
return 0;
}
#define OFFSET(x) offsetof(CLJRContext, x)
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "dither_type", "Dither type", OFFSET(dither_type), AV_OPT_TYPE_INT, { .i64=1 }, 0, 2, VE},
{ NULL },
};
static const AVClass cljr_class = {
.class_name = "cljr encoder",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVCodec ff_cljr_encoder = {
.name = "cljr",
.long_name = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_CLJR,
.capabilities = AV_CODEC_CAP_DR1,
.priv_data_size = sizeof(CLJRContext),
.encode2 = encode_frame,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV411P,
AV_PIX_FMT_NONE },
.priv_class = &cljr_class,
};