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libavcodec/pcxenc.c

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00001 /*
00002  * PC Paintbrush PCX (.pcx) image encoder
00003  * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00029 #include "avcodec.h"
00030 #include "bytestream.h"
00031 
00032 typedef struct PCXContext {
00033     AVFrame picture;
00034 } PCXContext;
00035 
00036 static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
00037 
00038 static av_cold int pcx_encode_init(AVCodecContext *avctx)
00039 {
00040     PCXContext *s = avctx->priv_data;
00041 
00042     avcodec_get_frame_defaults(&s->picture);
00043     avctx->coded_frame = &s->picture;
00044 
00045     return 0;
00046 }
00047 
00058 static int pcx_rle_encode(      uint8_t *dst, int dst_size,
00059                           const uint8_t *src, int src_plane_size, int nplanes)
00060 {
00061     int p;
00062     const uint8_t *dst_start = dst;
00063 
00064     // check worst-case upper bound on dst_size
00065     if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
00066         return -1;
00067 
00068     for (p = 0; p < nplanes; p++) {
00069         int count = 1;
00070         const uint8_t *src_plane = src + p;
00071         const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
00072         uint8_t prev = *src_plane;
00073         src_plane += nplanes;
00074 
00075         for (; ; src_plane += nplanes) {
00076             if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
00077                 // current byte is same as prev
00078                 ++count;
00079             } else {
00080                 // output prev * count
00081                 if (count != 1 || prev >= 0xC0)
00082                     *dst++ = 0xC0 | count;
00083                 *dst++ = prev;
00084 
00085                 if (src_plane == src_plane_end)
00086                     break;
00087 
00088                 // start new run
00089                 count = 1;
00090                 prev = *src_plane;
00091             }
00092         }
00093     }
00094 
00095     return dst - dst_start;
00096 }
00097 
00098 static int pcx_encode_frame(AVCodecContext *avctx,
00099                             unsigned char *buf, int buf_size, void *data)
00100 {
00101     PCXContext *s = avctx->priv_data;
00102     AVFrame *const pict = &s->picture;
00103     const uint8_t *buf_start = buf;
00104     const uint8_t *buf_end   = buf + buf_size;
00105 
00106     int bpp, nplanes, i, y, line_bytes, written;
00107     const uint32_t *pal = NULL;
00108     const uint8_t *src;
00109 
00110     *pict = *(AVFrame *)data;
00111     pict->pict_type = FF_I_TYPE;
00112     pict->key_frame = 1;
00113 
00114     if (avctx->width > 65535 || avctx->height > 65535) {
00115         av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
00116         return -1;
00117     }
00118 
00119     switch (avctx->pix_fmt) {
00120     case PIX_FMT_RGB24:
00121         bpp = 8;
00122         nplanes = 3;
00123         break;
00124     case PIX_FMT_RGB8:
00125     case PIX_FMT_BGR8:
00126     case PIX_FMT_RGB4_BYTE:
00127     case PIX_FMT_BGR4_BYTE:
00128     case PIX_FMT_GRAY8:
00129     case PIX_FMT_PAL8:
00130         bpp = 8;
00131         nplanes = 1;
00132         pal = (uint32_t *)pict->data[1];
00133         break;
00134     case PIX_FMT_MONOBLACK:
00135         bpp = 1;
00136         nplanes = 1;
00137         pal = monoblack_pal;
00138         break;
00139     default:
00140         av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
00141         return -1;
00142     }
00143 
00144     line_bytes = (avctx->width * bpp + 7) >> 3;
00145     line_bytes = (line_bytes + 1) & ~1;
00146 
00147     bytestream_put_byte(&buf, 10);                  // manufacturer
00148     bytestream_put_byte(&buf, 5);                   // version
00149     bytestream_put_byte(&buf, 1);                   // encoding
00150     bytestream_put_byte(&buf, bpp);                 // bits per pixel per plane
00151     bytestream_put_le16(&buf, 0);                   // x min
00152     bytestream_put_le16(&buf, 0);                   // y min
00153     bytestream_put_le16(&buf, avctx->width - 1);    // x max
00154     bytestream_put_le16(&buf, avctx->height - 1);   // y max
00155     bytestream_put_le16(&buf, 0);                   // horizontal DPI
00156     bytestream_put_le16(&buf, 0);                   // vertical DPI
00157     for (i = 0; i < 16; i++)
00158         bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
00159     bytestream_put_byte(&buf, 0);                   // reserved
00160     bytestream_put_byte(&buf, nplanes);             // number of planes
00161     bytestream_put_le16(&buf, line_bytes);          // scanline plane size in bytes
00162 
00163     while (buf - buf_start < 128)
00164         *buf++= 0;
00165 
00166     src = pict->data[0];
00167 
00168     for (y = 0; y < avctx->height; y++) {
00169         if ((written = pcx_rle_encode(buf, buf_end - buf,
00170                                       src, line_bytes, nplanes)) < 0) {
00171             av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
00172             return -1;
00173         }
00174         buf += written;
00175         src += pict->linesize[0];
00176     }
00177 
00178     if (nplanes == 1 && bpp == 8) {
00179         if (buf_end - buf < 257) {
00180             av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
00181             return -1;
00182         }
00183         bytestream_put_byte(&buf, 12);
00184         for (i = 0; i < 256; i++) {
00185             bytestream_put_be24(&buf, pal[i]);
00186         }
00187     }
00188 
00189     return buf - buf_start;
00190 }
00191 
00192 AVCodec pcx_encoder = {
00193     "pcx",
00194     AVMEDIA_TYPE_VIDEO,
00195     CODEC_ID_PCX,
00196     sizeof(PCXContext),
00197     pcx_encode_init,
00198     pcx_encode_frame,
00199     NULL,
00200     .pix_fmts = (const enum PixelFormat[]){
00201         PIX_FMT_RGB24,
00202         PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
00203         PIX_FMT_MONOBLACK,
00204         PIX_FMT_NONE},
00205     .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
00206 };

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