yading@10: /*
yading@10:  * XBM image format
yading@10:  *
yading@10:  * Copyright (c) 2012 Paul B Mahol
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "internal.h"
yading@10: #include "mathops.h"
yading@10: #include "libavutil/avstring.h"
yading@10: 
yading@10: static av_cold int xbm_decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int convert(uint8_t x)
yading@10: {
yading@10:     if (x >= 'a')
yading@10:         x -= 87;
yading@10:     else if (x >= 'A')
yading@10:         x -= 55;
yading@10:     else
yading@10:         x -= '0';
yading@10:     return x;
yading@10: }
yading@10: 
yading@10: static int xbm_decode_frame(AVCodecContext *avctx, void *data,
yading@10:                             int *got_frame, AVPacket *avpkt)
yading@10: {
yading@10:     AVFrame *p = data;
yading@10:     const uint8_t *end, *ptr = avpkt->data;
yading@10:     uint8_t *dst;
yading@10:     int ret, linesize, i, j;
yading@10: 
yading@10:     end = avpkt->data + avpkt->size;
yading@10:     while (!avctx->width || !avctx->height) {
yading@10:         char name[256];
yading@10:         int number, len;
yading@10: 
yading@10:         ptr += strcspn(ptr, "#");
yading@10:         if (sscanf(ptr, "#define %256s %u", name, &number) != 2) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "Unexpected preprocessor directive\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10: 
yading@10:         len = strlen(name);
yading@10:         if ((len > 6) && !avctx->height && !memcmp(name + len - 7, "_height", 7)) {
yading@10:                 avctx->height = number;
yading@10:         } else if ((len > 5) && !avctx->width && !memcmp(name + len - 6, "_width", 6)) {
yading@10:                 avctx->width = number;
yading@10:         } else {
yading@10:             av_log(avctx, AV_LOG_ERROR, "Unknown define '%s'\n", name);
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10:         ptr += strcspn(ptr, "\n\r") + 1;
yading@10:     }
yading@10: 
yading@10:     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     // goto start of image data
yading@10:     ptr += strcspn(ptr, "{") + 1;
yading@10: 
yading@10:     linesize = (avctx->width + 7) / 8;
yading@10:     for (i = 0; i < avctx->height; i++) {
yading@10:         dst = p->data[0] + i * p->linesize[0];
yading@10:         for (j = 0; j < linesize; j++) {
yading@10:             uint8_t val;
yading@10: 
yading@10:             ptr += strcspn(ptr, "x") + 1;
yading@10:             if (ptr < end && av_isxdigit(*ptr)) {
yading@10:                 val = convert(*ptr);
yading@10:                 ptr++;
yading@10:                 if (av_isxdigit(*ptr))
yading@10:                     val = (val << 4) + convert(*ptr);
yading@10:                 *dst++ = ff_reverse[val];
yading@10:             } else {
yading@10:                 av_log(avctx, AV_LOG_ERROR, "Unexpected data at '%.8s'\n", ptr);
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     p->key_frame = 1;
yading@10:     p->pict_type = AV_PICTURE_TYPE_I;
yading@10: 
yading@10:     *got_frame       = 1;
yading@10: 
yading@10:     return avpkt->size;
yading@10: }
yading@10: 
yading@10: AVCodec ff_xbm_decoder = {
yading@10:     .name         = "xbm",
yading@10:     .type         = AVMEDIA_TYPE_VIDEO,
yading@10:     .id           = AV_CODEC_ID_XBM,
yading@10:     .init         = xbm_decode_init,
yading@10:     .decode       = xbm_decode_frame,
yading@10:     .capabilities = CODEC_CAP_DR1,
yading@10:     .long_name    = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"),
yading@10: };