2 * Microsoft Video-1 Encoder
3 * Copyright (c) 2009 Konstantin Shishkov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Microsoft Video-1 encoder
28 #include "bytestream.h"
29 #include "libavutil/lfg.h"
31 #include "libavutil/imgutils.h"
35 typedef struct Msvideo1EncContext {
36 AVCodecContext *avctx;
59 #define SKIP_PREFIX 0x8400
60 #define SKIPS_MAX 0x0FFF
61 #define MKRGB555(in, off) ((in[off] << 10) | (in[off + 1] << 5) | (in[off + 2]))
63 static const int remap[16] = { 0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15 };
65 static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
67 Msvideo1EncContext * const c = avctx->priv_data;
69 AVFrame * const p = &c->pic;
80 c->prev = av_malloc(avctx->width * 3 * (avctx->height + 3));
81 prevptr = c->prev + avctx->width * 3 * (FFALIGN(avctx->height, 4) - 1);
82 src = (uint16_t*)(p->data[0] + p->linesize[0]*(FFALIGN(avctx->height, 4) - 1));
83 if(c->keyint >= avctx->keyint_min)
88 for(y = 0; y < avctx->height; y += 4){
89 for(x = 0; x < avctx->width; x += 4){
90 int bestmode = MODE_SKIP;
91 int bestscore = INT_MAX;
95 for(j = 0; j < 4; j++){
96 for(i = 0; i < 4; i++){
97 uint16_t val = src[x + i - j*p->linesize[0]/2];
98 for(k = 0; k < 3; k++){
99 c->block[(i + j*4)*3 + k] =
100 c->block2[remap[i + j*4]*3 + k] = (val >> (10-k*5)) & 0x1F;
106 for(j = 0; j < 4; j++){
107 for(i = 0; i < 4*3; i++){
108 int t = prevptr[x*3 + i + j*p->linesize[0]] - c->block[i + j*4*3];
112 bestscore /= p->quality;
114 // try to find optimal value to fill whole 4x4 block
116 ff_init_elbg(c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
117 ff_do_elbg (c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
118 if(c->avg[0] == 1) // red component = 1 will be written as skip code
120 for(j = 0; j < 4; j++){
121 for(i = 0; i < 4; i++){
122 for(k = 0; k < 3; k++){
123 int t = c->avg[k] - c->block[(i+j*4)*3+k];
130 if(score < bestscore){
132 bestmode = MODE_FILL;
134 // search for optimal filling of 2-color block
136 ff_init_elbg(c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
137 ff_do_elbg (c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
138 // last output value should be always 1, swap codebooks if needed
140 for(i = 0; i < 3; i++)
141 FFSWAP(uint8_t, c->codebook[i], c->codebook[i+3]);
142 for(i = 0; i < 16; i++)
145 for(j = 0; j < 4; j++){
146 for(i = 0; i < 4; i++){
147 for(k = 0; k < 3; k++){
148 int t = c->codebook[c->output[i+j*4]*3 + k] - c->block[i*3+k+j*4*3];
155 if(score < bestscore){
157 bestmode = MODE_2COL;
159 // search for optimal filling of 2-color 2x2 subblocks
161 for(i = 0; i < 4; i++){
162 ff_init_elbg(c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
163 ff_do_elbg (c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
165 // last value should be always 1, swap codebooks if needed
167 for(i = 0; i < 3; i++)
168 FFSWAP(uint8_t, c->codebook2[i+18], c->codebook2[i+21]);
169 for(i = 12; i < 16; i++)
172 for(j = 0; j < 4; j++){
173 for(i = 0; i < 4; i++){
174 for(k = 0; k < 3; k++){
175 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];
182 if(score < bestscore){
184 bestmode = MODE_8COL;
187 if(bestmode == MODE_SKIP){
191 if((bestmode != MODE_SKIP && skips) || skips == SKIPS_MAX){
192 bytestream_put_le16(&dst, skips | SKIP_PREFIX);
198 bytestream_put_le16(&dst, MKRGB555(c->avg,0) | 0x8000);
199 for(j = 0; j < 4; j++)
200 for(i = 0; i < 4; i++)
201 for(k = 0; k < 3; k++)
202 prevptr[i*3 + k - j*3*avctx->width] = c->avg[k];
205 for(j = 0; j < 4; j++){
206 for(i = 0; i < 4; i++){
207 flags |= (c->output[i + j*4]^1) << (i + j*4);
208 for(k = 0; k < 3; k++)
209 prevptr[i*3 + k - j*3*avctx->width] = c->codebook[c->output[i + j*4]*3 + k];
212 bytestream_put_le16(&dst, flags);
213 bytestream_put_le16(&dst, MKRGB555(c->codebook, 0));
214 bytestream_put_le16(&dst, MKRGB555(c->codebook, 3));
217 for(j = 0; j < 4; j++){
218 for(i = 0; i < 4; i++){
219 flags |= (c->output2[remap[i + j*4]]^1) << (i + j*4);
220 for(k = 0; k < 3; k++)
221 prevptr[i*3 + k - j*3*avctx->width] = c->codebook2[(c->output2[remap[i+j*4]] + (i&2) + (j&2)*2)*3 + k];
224 bytestream_put_le16(&dst, flags);
225 bytestream_put_le16(&dst, MKRGB555(c->codebook2, 0) | 0x8000);
226 for(i = 3; i < 24; i += 3)
227 bytestream_put_le16(&dst, MKRGB555(c->codebook2, i));
231 src -= p->linesize[0] << 1;
232 prevptr -= avctx->width * 3 * 4;
235 bytestream_put_le16(&dst, skips | SKIP_PREFIX);
237 bytestream_put_byte(&dst, 0);
238 bytestream_put_byte(&dst, 0);
246 p->pict_type= keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
247 p->key_frame= keyframe;
256 static av_cold int encode_init(AVCodecContext *avctx)
258 Msvideo1EncContext * const c = avctx->priv_data;
261 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
264 if((avctx->width&3) || (avctx->height&3)){
265 av_log(avctx, AV_LOG_ERROR, "width and height must be multiplies of 4\n");
269 avcodec_get_frame_defaults(&c->pic);
270 avctx->coded_frame = (AVFrame*)&c->pic;
272 c->keyint = avctx->keyint_min;
273 av_lfg_init(&c->rnd, 1);
283 static av_cold int encode_end(AVCodecContext *avctx)
285 Msvideo1EncContext * const c = avctx->priv_data;
292 AVCodec ff_msvideo1_encoder = {
294 .type = AVMEDIA_TYPE_VIDEO,
295 .id = CODEC_ID_MSVIDEO1,
296 .priv_data_size = sizeof(Msvideo1EncContext),
298 .encode = encode_frame,
300 .pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB555, PIX_FMT_NONE},
301 .long_name = NULL_IF_CONFIG_SMALL("Microsoft Video-1"),