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