libavcodec/pcxenc.c

   1 /*
   2  * PC Paintbrush PCX (.pcx) image encoder
   3  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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.
  11  *
  12  * Libav 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.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * PCX image encoder
  25  * @author Daniel Verkamp
  26  * @see http://www.qzx.com/pc-gpe/pcx.txt
  27  */
  28
  29 #include "avcodec.h"
  30 #include "bytestream.h"
  31 #include "internal.h"
  32
  33 typedef struct PCXContext {
  34     AVFrame picture;
  35 } PCXContext;
  36
  37 static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
  38
  39 static av_cold int pcx_encode_init(AVCodecContext *avctx)
  40 {
  41     PCXContext *s = avctx->priv_data;
  42
  43     avcodec_get_frame_defaults(&s->picture);
  44     avctx->coded_frame = &s->picture;
  45
  46     return 0;
  47 }
  48
  49 /**
  50  * PCX run-length encoder
  51  * @param dst output buffer
  52  * @param dst_size size of output buffer
  53  * @param src input buffer
  54  * @param src_plane_size size of one plane of input buffer in bytes
  55  * @param nplanes number of planes in input buffer
  56  * @return number of bytes written to dst or -1 on error
  57  * @bug will not work for nplanes != 1 && bpp != 8
  58  */
  59 static int pcx_rle_encode(      uint8_t *dst, int dst_size,
  60                           const uint8_t *src, int src_plane_size, int nplanes)
  61 {
  62     int p;
  63     const uint8_t *dst_start = dst;
  64
  65     // check worst-case upper bound on dst_size
  66     if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
  67         return -1;
  68
  69     for (p = 0; p < nplanes; p++) {
  70         int count = 1;
  71         const uint8_t *src_plane = src + p;
  72         const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
  73         uint8_t prev = *src_plane;
  74         src_plane += nplanes;
  75
  76         for (; ; src_plane += nplanes) {
  77             if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
  78                 // current byte is same as prev
  79                 ++count;
  80             } else {
  81                 // output prev * count
  82                 if (count != 1 || prev >= 0xC0)
  83                     *dst++ = 0xC0 | count;
  84                 *dst++ = prev;
  85
  86                 if (src_plane == src_plane_end)
  87                     break;
  88
  89                 // start new run
  90                 count = 1;
  91                 prev = *src_plane;
  92             }
  93         }
  94     }
  95
  96     return dst - dst_start;
  97 }
  98
  99 static int pcx_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
 100                             const AVFrame *frame, int *got_packet)
 101 {
 102     PCXContext *s = avctx->priv_data;
 103     AVFrame *const pict = &s->picture;
 104     const uint8_t *buf_end;
 105     uint8_t *buf;
 106
 107     int bpp, nplanes, i, y, line_bytes, written, ret, max_pkt_size;
 108     const uint32_t *pal = NULL;
 109     const uint8_t *src;
 110
 111     *pict = *frame;
 112     pict->pict_type = AV_PICTURE_TYPE_I;
 113     pict->key_frame = 1;
 114
 115     if (avctx->width > 65535 || avctx->height > 65535) {
 116         av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
 117         return -1;
 118     }
 119
 120     switch (avctx->pix_fmt) {
 121     case AV_PIX_FMT_RGB24:
 122         bpp = 8;
 123         nplanes = 3;
 124         break;
 125     case AV_PIX_FMT_RGB8:
 126     case AV_PIX_FMT_BGR8:
 127     case AV_PIX_FMT_RGB4_BYTE:
 128     case AV_PIX_FMT_BGR4_BYTE:
 129     case AV_PIX_FMT_GRAY8:
 130     case AV_PIX_FMT_PAL8:
 131         bpp = 8;
 132         nplanes = 1;
 133         pal = (uint32_t *)pict->data[1];
 134         break;
 135     case AV_PIX_FMT_MONOBLACK:
 136         bpp = 1;
 137         nplanes = 1;
 138         pal = monoblack_pal;
 139         break;
 140     default:
 141         av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
 142         return -1;
 143     }
 144
 145     line_bytes = (avctx->width * bpp + 7) >> 3;
 146     line_bytes = (line_bytes + 1) & ~1;
 147
 148     max_pkt_size = 128 + avctx->height * 2 * line_bytes * nplanes + (pal ? 256*3 + 1 : 0);
 149     if ((ret = ff_alloc_packet(pkt, max_pkt_size)) < 0) {
 150         av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", max_pkt_size);
 151         return ret;
 152     }
 153     buf     = pkt->data;
 154     buf_end = pkt->data + pkt->size;
 155
 156     bytestream_put_byte(&buf, 10);                  // manufacturer
 157     bytestream_put_byte(&buf, 5);                   // version
 158     bytestream_put_byte(&buf, 1);                   // encoding
 159     bytestream_put_byte(&buf, bpp);                 // bits per pixel per plane
 160     bytestream_put_le16(&buf, 0);                   // x min
 161     bytestream_put_le16(&buf, 0);                   // y min
 162     bytestream_put_le16(&buf, avctx->width - 1);    // x max
 163     bytestream_put_le16(&buf, avctx->height - 1);   // y max
 164     bytestream_put_le16(&buf, 0);                   // horizontal DPI
 165     bytestream_put_le16(&buf, 0);                   // vertical DPI
 166     for (i = 0; i < 16; i++)
 167         bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
 168     bytestream_put_byte(&buf, 0);                   // reserved
 169     bytestream_put_byte(&buf, nplanes);             // number of planes
 170     bytestream_put_le16(&buf, line_bytes);          // scanline plane size in bytes
 171
 172     while (buf - pkt->data < 128)
 173         *buf++= 0;
 174
 175     src = pict->data[0];
 176
 177     for (y = 0; y < avctx->height; y++) {
 178         if ((written = pcx_rle_encode(buf, buf_end - buf,
 179                                       src, line_bytes, nplanes)) < 0) {
 180             av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
 181             return -1;
 182         }
 183         buf += written;
 184         src += pict->linesize[0];
 185     }
 186
 187     if (nplanes == 1 && bpp == 8) {
 188         if (buf_end - buf < 257) {
 189             av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
 190             return -1;
 191         }
 192         bytestream_put_byte(&buf, 12);
 193         for (i = 0; i < 256; i++) {
 194             bytestream_put_be24(&buf, pal[i]);
 195         }
 196     }
 197
 198     pkt->size   = buf - pkt->data;
 199     pkt->flags |= AV_PKT_FLAG_KEY;
 200     *got_packet = 1;
 201
 202     return 0;
 203 }
 204
 205 AVCodec ff_pcx_encoder = {
 206     .name           = "pcx",
 207     .type           = AVMEDIA_TYPE_VIDEO,
 208     .id             = AV_CODEC_ID_PCX,
 209     .priv_data_size = sizeof(PCXContext),
 210     .init           = pcx_encode_init,
 211     .encode2        = pcx_encode_frame,
 212     .pix_fmts       = (const enum AVPixelFormat[]){
 213         AV_PIX_FMT_RGB24,
 214         AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
 215         AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8,
 216         AV_PIX_FMT_MONOBLACK,
 217         AV_PIX_FMT_NONE
 218     },
 219     .long_name      = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
 220 };