xref: /third_party/ffmpeg/libavcodec/qoienc.c (revision cabdff1a)
1/*
2 * QOI image format encoder
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "libavutil/imgutils.h"
22#include "avcodec.h"
23#include "bytestream.h"
24#include "codec_internal.h"
25#include "encode.h"
26#include "qoi.h"
27
28static int qoi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
29                            const AVFrame *pict, int *got_packet)
30{
31    const int channels = 3 + (avctx->pix_fmt == AV_PIX_FMT_RGBA);
32    uint8_t px_prev[4] = { 0, 0, 0, 255 };
33    uint8_t px[4] = { 0, 0, 0, 255 };
34    uint8_t index[64][4] = { 0 };
35    int64_t packet_size;
36    uint8_t *buf, *src;
37    int ret, run = 0;
38
39    packet_size = avctx->width * avctx->height * (channels + 1LL) + 14LL + 8LL;
40    if ((ret = ff_alloc_packet(avctx, pkt, packet_size)) < 0)
41        return ret;
42
43    buf = pkt->data;
44    src = pict->data[0];
45
46    bytestream_put_buffer(&buf, "qoif", 4);
47    bytestream_put_be32(&buf, avctx->width);
48    bytestream_put_be32(&buf, avctx->height);
49    bytestream_put_byte(&buf, channels);
50    bytestream_put_byte(&buf, avctx->color_trc == AVCOL_TRC_LINEAR);
51
52    for (int y = 0; y < avctx->height; y++) {
53        for (int x = 0; x < avctx->width; x++) {
54            memcpy(px, src + x * channels, channels);
55
56            if (!memcmp(px, px_prev, 4)) {
57                run++;
58                if (run == 62) {
59                    bytestream_put_byte(&buf, QOI_OP_RUN | (run - 1));
60                    run = 0;
61                }
62            } else {
63                int index_pos;
64
65                if (run > 0) {
66                    bytestream_put_byte(&buf, QOI_OP_RUN | (run - 1));
67                    run = 0;
68                }
69
70                index_pos = QOI_COLOR_HASH(px) & 63;
71
72                if (!memcmp(index[index_pos], px, 4)) {
73                    bytestream_put_byte(&buf, QOI_OP_INDEX | index_pos);
74                } else {
75                    memcpy(index[index_pos], px, 4);
76
77                    if (px[3] == px_prev[3]) {
78                        int8_t vr = px[0] - px_prev[0];
79                        int8_t vg = px[1] - px_prev[1];
80                        int8_t vb = px[2] - px_prev[2];
81
82                        int8_t vg_r = vr - vg;
83                        int8_t vg_b = vb - vg;
84
85                        if (vr > -3 && vr < 2 &&
86                            vg > -3 && vg < 2 &&
87                            vb > -3 && vb < 2) {
88                            bytestream_put_byte(&buf, QOI_OP_DIFF | (vr + 2) << 4 | (vg + 2) << 2 | (vb + 2));
89                        } else if (vg_r >  -9 && vg_r <  8 &&
90                                   vg   > -33 && vg   < 32 &&
91                                   vg_b >  -9 && vg_b <  8) {
92                            bytestream_put_byte(&buf, QOI_OP_LUMA     | (vg   + 32));
93                            bytestream_put_byte(&buf, (vg_r + 8) << 4 | (vg_b +  8));
94                        } else {
95                            bytestream_put_byte(&buf, QOI_OP_RGB);
96                            bytestream_put_byte(&buf, px[0]);
97                            bytestream_put_byte(&buf, px[1]);
98                            bytestream_put_byte(&buf, px[2]);
99                        }
100                    } else {
101                        bytestream_put_byte(&buf, QOI_OP_RGBA);
102                        bytestream_put_byte(&buf, px[0]);
103                        bytestream_put_byte(&buf, px[1]);
104                        bytestream_put_byte(&buf, px[2]);
105                        bytestream_put_byte(&buf, px[3]);
106                    }
107                }
108            }
109
110            memcpy(px_prev, px, 4);
111        }
112
113        src += pict->linesize[0];
114    }
115
116    if (run)
117        bytestream_put_byte(&buf, QOI_OP_RUN | (run - 1));
118
119    bytestream_put_be64(&buf, 0x01);
120
121    pkt->size = buf - pkt->data;
122
123    *got_packet = 1;
124
125    return 0;
126}
127
128const FFCodec ff_qoi_encoder = {
129    .p.name         = "qoi",
130    .p.long_name    = NULL_IF_CONFIG_SMALL("QOI (Quite OK Image format) image"),
131    .p.type         = AVMEDIA_TYPE_VIDEO,
132    .p.id           = AV_CODEC_ID_QOI,
133    .p.capabilities = AV_CODEC_CAP_FRAME_THREADS,
134    FF_CODEC_ENCODE_CB(qoi_encode_frame),
135    .p.pix_fmts     = (const enum AVPixelFormat[]){
136        AV_PIX_FMT_RGBA, AV_PIX_FMT_RGB24,
137        AV_PIX_FMT_NONE
138    },
139    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
140};
141