libavcodec/qoienc.c

   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
  28 static 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;
  37     const uint8_t *src;
  38     int ret, run = 0;
  39
  40     packet_size = avctx->width * avctx->height * (channels + 1LL) + 14LL + 8LL;
  41     if ((ret = ff_alloc_packet(avctx, pkt, packet_size)) < 0)
  42         return ret;
  43
  44     buf = pkt->data;
  45     src = pict->data[0];
  46
  47     bytestream_put_buffer(&buf, "qoif", 4);
  48     bytestream_put_be32(&buf, avctx->width);
  49     bytestream_put_be32(&buf, avctx->height);
  50     bytestream_put_byte(&buf, channels);
  51     bytestream_put_byte(&buf, avctx->color_trc == AVCOL_TRC_LINEAR);
  52
  53     for (int y = 0; y < avctx->height; y++) {
  54         for (int x = 0; x < avctx->width; x++) {
  55             memcpy(px, src + x * channels, channels);
  56
  57             if (!memcmp(px, px_prev, 4)) {
  58                 run++;
  59                 if (run == 62) {
  60                     bytestream_put_byte(&buf, QOI_OP_RUN | (run - 1));
  61                     run = 0;
  62                 }
  63             } else {
  64                 int index_pos;
  65
  66                 if (run > 0) {
  67                     bytestream_put_byte(&buf, QOI_OP_RUN | (run - 1));
  68                     run = 0;
  69                 }
  70
  71                 index_pos = QOI_COLOR_HASH(px) & 63;
  72
  73                 if (!memcmp(index[index_pos], px, 4)) {
  74                     bytestream_put_byte(&buf, QOI_OP_INDEX | index_pos);
  75                 } else {
  76                     memcpy(index[index_pos], px, 4);
  77
  78                     if (px[3] == px_prev[3]) {
  79                         int8_t vr = px[0] - px_prev[0];
  80                         int8_t vg = px[1] - px_prev[1];
  81                         int8_t vb = px[2] - px_prev[2];
  82
  83                         int8_t vg_r = vr - vg;
  84                         int8_t vg_b = vb - vg;
  85
  86                         if (vr > -3 && vr < 2 &&
  87                             vg > -3 && vg < 2 &&
  88                             vb > -3 && vb < 2) {
  89                             bytestream_put_byte(&buf, QOI_OP_DIFF | (vr + 2) << 4 | (vg + 2) << 2 | (vb + 2));
  90                         } else if (vg_r >  -9 && vg_r <  8 &&
  91                                    vg   > -33 && vg   < 32 &&
  92                                    vg_b >  -9 && vg_b <  8) {
  93                             bytestream_put_byte(&buf, QOI_OP_LUMA     | (vg   + 32));
  94                             bytestream_put_byte(&buf, (vg_r + 8) << 4 | (vg_b +  8));
  95                         } else {
  96                             bytestream_put_byte(&buf, QOI_OP_RGB);
  97                             bytestream_put_byte(&buf, px[0]);
  98                             bytestream_put_byte(&buf, px[1]);
  99                             bytestream_put_byte(&buf, px[2]);
 100                         }
 101                     } else {
 102                         bytestream_put_byte(&buf, QOI_OP_RGBA);
 103                         bytestream_put_byte(&buf, px[0]);
 104                         bytestream_put_byte(&buf, px[1]);
 105                         bytestream_put_byte(&buf, px[2]);
 106                         bytestream_put_byte(&buf, px[3]);
 107                     }
 108                 }
 109             }
 110
 111             memcpy(px_prev, px, 4);
 112         }
 113
 114         src += pict->linesize[0];
 115     }
 116
 117     if (run)
 118         bytestream_put_byte(&buf, QOI_OP_RUN | (run - 1));
 119
 120     bytestream_put_be64(&buf, 0x01);
 121
 122     pkt->size = buf - pkt->data;
 123
 124     *got_packet = 1;
 125
 126     return 0;
 127 }
 128
 129 const FFCodec ff_qoi_encoder = {
 130     .p.name         = "qoi",
 131     CODEC_LONG_NAME("QOI (Quite OK Image format) image"),
 132     .p.type         = AVMEDIA_TYPE_VIDEO,
 133     .p.id           = AV_CODEC_ID_QOI,
 134     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
 135                       AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
 136     FF_CODEC_ENCODE_CB(qoi_encode_frame),
 137     .p.pix_fmts     = (const enum AVPixelFormat[]){
 138         AV_PIX_FMT_RGBA, AV_PIX_FMT_RGB24,
 139         AV_PIX_FMT_NONE
 140     },
 141 };