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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-28 20:53:54 +02:00
FFmpeg/libavcodec/msvideo1enc.c
Andreas Rheinhardt 56e9e0273a avcodec/encode: Always use intermediate buffer in ff_alloc_packet2()
Up until now, ff_alloc_packet2() has a min_size parameter:
It is supposed to be a lower bound on the final size of the packet
to allocate. If it is not too far from the upper bound (namely,
if it is at least half the upper bound), then ff_alloc_packet2()
already allocates the final, already refcounted packet; if it is
not, then the packet is not refcounted and its data only points to
a buffer owned by the AVCodecContext (in this case, the packet will
be made refcounted in encode_simple_internal() in libavcodec/encode.c).
The goal of this was to avoid data copies and intermediate buffers
if one has a precise lower bound.

Yet those encoders for which precise lower bounds exist have recently
been switched to ff_get_encode_buffer() (which automatically allocates
final buffers), leaving only two encoders to actually set the min_size
to something else than zero (namely aliaspixenc and hapenc). Both of
these encoders use a very low lower bound that is not helpful in any
nontrivial case.

This commit therefore removes the min_size parameter as well as the
codepath in ff_alloc_packet2() for the allocation of final buffers.
Furthermore, the function has been renamed to ff_alloc_packet() and
moved to encode.h alongside ff_get_encode_buffer().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2021-06-08 12:52:50 +02:00

308 lines
10 KiB
C

/*
* Microsoft Video-1 Encoder
* Copyright (c) 2009 Konstantin Shishkov
*
* 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
* Microsoft Video-1 encoder
*/
#include "avcodec.h"
#include "encode.h"
#include "internal.h"
#include "bytestream.h"
#include "libavutil/lfg.h"
#include "elbg.h"
#include "libavutil/imgutils.h"
/**
* Encoder context
*/
typedef struct Msvideo1EncContext {
AVCodecContext *avctx;
AVLFG rnd;
uint8_t *prev;
int block[16*3];
int block2[16*3];
int codebook[8*3];
int codebook2[8*3];
int output[16*3];
int output2[16*3];
int avg[3];
int bestpos;
int keyint;
} Msvideo1EncContext;
enum MSV1Mode{
MODE_SKIP = 0,
MODE_FILL,
MODE_2COL,
MODE_8COL,
};
#define SKIP_PREFIX 0x8400
#define SKIPS_MAX 0x03FF
#define MKRGB555(in, off) (((in)[off] << 10) | ((in)[(off) + 1] << 5) | ((in)[(off) + 2]))
static const int remap[16] = { 0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15 };
static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *pict, int *got_packet)
{
Msvideo1EncContext * const c = avctx->priv_data;
const AVFrame *p = pict;
uint16_t *src;
uint8_t *prevptr;
uint8_t *dst, *buf;
int keyframe = 0;
int no_skips = 1;
int i, j, k, x, y, ret;
int skips = 0;
int quality = 24;
if ((ret = ff_alloc_packet(avctx, pkt, avctx->width*avctx->height*9 + AV_INPUT_BUFFER_MIN_SIZE)) < 0)
return ret;
dst= buf= pkt->data;
if(!c->prev)
c->prev = av_malloc(avctx->width * 3 * (avctx->height + 3));
prevptr = c->prev + avctx->width * 3 * (FFALIGN(avctx->height, 4) - 1);
src = (uint16_t*)(p->data[0] + p->linesize[0]*(FFALIGN(avctx->height, 4) - 1));
if(c->keyint >= avctx->keyint_min)
keyframe = 1;
for(y = 0; y < avctx->height; y += 4){
for(x = 0; x < avctx->width; x += 4){
int bestmode = MODE_SKIP;
int bestscore = INT_MAX;
int flags = 0;
int score;
for(j = 0; j < 4; j++){
for(i = 0; i < 4; i++){
uint16_t val = src[x + i - j*p->linesize[0]/2];
for(k = 0; k < 3; k++){
c->block[(i + j*4)*3 + k] =
c->block2[remap[i + j*4]*3 + k] = (val >> (10-k*5)) & 0x1F;
}
}
}
if(!keyframe){
bestscore = 0;
for(j = 0; j < 4; j++){
for(i = 0; i < 4*3; i++){
int t = prevptr[x*3 + i - j*3*avctx->width] - c->block[i + j*4*3];
bestscore += t*t;
}
}
bestscore /= quality;
}
// try to find optimal value to fill whole 4x4 block
score = 0;
avpriv_init_elbg(c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
avpriv_do_elbg (c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
if(c->avg[0] == 1) // red component = 1 will be written as skip code
c->avg[0] = 0;
for(j = 0; j < 4; j++){
for(i = 0; i < 4; i++){
for(k = 0; k < 3; k++){
int t = c->avg[k] - c->block[(i+j*4)*3+k];
score += t*t;
}
}
}
score /= quality;
score += 2;
if(score < bestscore){
bestscore = score;
bestmode = MODE_FILL;
}
// search for optimal filling of 2-color block
score = 0;
avpriv_init_elbg(c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
avpriv_do_elbg (c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
// last output value should be always 1, swap codebooks if needed
if(!c->output[15]){
for(i = 0; i < 3; i++)
FFSWAP(uint8_t, c->codebook[i], c->codebook[i+3]);
for(i = 0; i < 16; i++)
c->output[i] ^= 1;
}
for(j = 0; j < 4; j++){
for(i = 0; i < 4; i++){
for(k = 0; k < 3; k++){
int t = c->codebook[c->output[i+j*4]*3 + k] - c->block[i*3+k+j*4*3];
score += t*t;
}
}
}
score /= quality;
score += 6;
if(score < bestscore){
bestscore = score;
bestmode = MODE_2COL;
}
// search for optimal filling of 2-color 2x2 subblocks
score = 0;
for(i = 0; i < 4; i++){
avpriv_init_elbg(c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
avpriv_do_elbg (c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
}
// last value should be always 1, swap codebooks if needed
if(!c->output2[15]){
for(i = 0; i < 3; i++)
FFSWAP(uint8_t, c->codebook2[i+18], c->codebook2[i+21]);
for(i = 12; i < 16; i++)
c->output2[i] ^= 1;
}
for(j = 0; j < 4; j++){
for(i = 0; i < 4; i++){
for(k = 0; k < 3; k++){
int t = c->codebook2[(c->output2[remap[i+j*4]] + (i&2) + (j&2)*2)*3+k] - c->block[i*3+k + j*4*3];
score += t*t;
}
}
}
score /= quality;
score += 18;
if(score < bestscore){
bestscore = score;
bestmode = MODE_8COL;
}
if(bestmode == MODE_SKIP){
skips++;
no_skips = 0;
}
if((bestmode != MODE_SKIP && skips) || skips == SKIPS_MAX){
bytestream_put_le16(&dst, skips | SKIP_PREFIX);
skips = 0;
}
switch(bestmode){
case MODE_FILL:
bytestream_put_le16(&dst, MKRGB555(c->avg,0) | 0x8000);
for(j = 0; j < 4; j++)
for(i = 0; i < 4; i++)
for(k = 0; k < 3; k++)
prevptr[x*3 + i*3 + k - j*3*avctx->width] = c->avg[k];
break;
case MODE_2COL:
for(j = 0; j < 4; j++){
for(i = 0; i < 4; i++){
flags |= (c->output[i + j*4]^1) << (i + j*4);
for(k = 0; k < 3; k++)
prevptr[x*3 + i*3 + k - j*3*avctx->width] = c->codebook[c->output[i + j*4]*3 + k];
}
}
bytestream_put_le16(&dst, flags);
bytestream_put_le16(&dst, MKRGB555(c->codebook, 0));
bytestream_put_le16(&dst, MKRGB555(c->codebook, 3));
break;
case MODE_8COL:
for(j = 0; j < 4; j++){
for(i = 0; i < 4; i++){
flags |= (c->output2[remap[i + j*4]]^1) << (i + j*4);
for(k = 0; k < 3; k++)
prevptr[x*3 + i*3 + k - j*3*avctx->width] = c->codebook2[(c->output2[remap[i+j*4]] + (i&2) + (j&2)*2)*3 + k];
}
}
bytestream_put_le16(&dst, flags);
bytestream_put_le16(&dst, MKRGB555(c->codebook2, 0) | 0x8000);
for(i = 3; i < 24; i += 3)
bytestream_put_le16(&dst, MKRGB555(c->codebook2, i));
break;
}
}
src -= p->linesize[0] << 1;
prevptr -= avctx->width * 3 * 4;
}
if(skips)
bytestream_put_le16(&dst, skips | SKIP_PREFIX);
//EOF
bytestream_put_byte(&dst, 0);
bytestream_put_byte(&dst, 0);
if(no_skips)
keyframe = 1;
if(keyframe)
c->keyint = 0;
else
c->keyint++;
if (keyframe) pkt->flags |= AV_PKT_FLAG_KEY;
pkt->size = dst - buf;
*got_packet = 1;
return 0;
}
/**
* init encoder
*/
static av_cold int encode_init(AVCodecContext *avctx)
{
Msvideo1EncContext * const c = avctx->priv_data;
c->avctx = avctx;
if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
return -1;
}
if((avctx->width&3) || (avctx->height&3)){
av_log(avctx, AV_LOG_ERROR, "width and height must be multiples of 4\n");
return -1;
}
avctx->bits_per_coded_sample = 16;
c->keyint = avctx->keyint_min;
av_lfg_init(&c->rnd, 1);
return 0;
}
/**
* Uninit encoder
*/
static av_cold int encode_end(AVCodecContext *avctx)
{
Msvideo1EncContext * const c = avctx->priv_data;
av_freep(&c->prev);
return 0;
}
const AVCodec ff_msvideo1_encoder = {
.name = "msvideo1",
.long_name = NULL_IF_CONFIG_SMALL("Microsoft Video-1"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSVIDEO1,
.priv_data_size = sizeof(Msvideo1EncContext),
.init = encode_init,
.encode2 = encode_frame,
.close = encode_end,
.pix_fmts = (const enum AVPixelFormat[]){AV_PIX_FMT_RGB555, AV_PIX_FMT_NONE},
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};