1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-26 19:01:44 +02:00
FFmpeg/libavcodec/cljrenc.c
Andreas Rheinhardt c81b8e04aa Avoid intermediate bitcount for number of bytes in PutBitContext
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2021-03-30 12:36:32 +02:00

123 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 "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;
}
if ((ret = ff_alloc_packet2(avctx, pkt, 32*avctx->height*avctx->width/4, 0)) < 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->size = put_bytes_output(&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,
};
AVCodec ff_cljr_encoder = {
.name = "cljr",
.long_name = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_CLJR,
.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,
};