From 678082b409aca711f9cf991df6b0200116489322 Mon Sep 17 00:00:00 2001 From: Vittorio Giovara Date: Sat, 22 Mar 2014 05:33:27 +0100 Subject: X-Bitmap decoder --- libavcodec/xbmdec.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 libavcodec/xbmdec.c (limited to 'libavcodec/xbmdec.c') diff --git a/libavcodec/xbmdec.c b/libavcodec/xbmdec.c new file mode 100644 index 0000000000..c26f3433fd --- /dev/null +++ b/libavcodec/xbmdec.c @@ -0,0 +1,122 @@ +/* + * XBM image format + * + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/avstring.h" + +#include "avcodec.h" +#include "internal.h" +#include "mathops.h" + +static int xbm_decode_frame(AVCodecContext *avctx, void *data, + int *got_frame, AVPacket *avpkt) +{ + AVFrame *p = data; + int ret, linesize, i; + int width = 0; + int height = 0; + const uint8_t *ptr = avpkt->data; + uint8_t *dst; + + avctx->pix_fmt = AV_PIX_FMT_MONOWHITE; + while (!width || !height) { + ptr += strcspn(ptr, "#"); + if (ptr >= avpkt->data + avpkt->size) { + av_log(avctx, AV_LOG_ERROR, "End of file reached.\n"); + return AVERROR_INVALIDDATA; + } + if (strncmp(ptr, "#define", 7) != 0) { + av_log(avctx, AV_LOG_ERROR, + "Unexpected preprocessor directive.\n"); + return AVERROR_INVALIDDATA; + } + // skip the name + ptr += strcspn(ptr, "_") + 1; + // get width or height + if (strncmp(ptr, "width", 5) == 0) { + ptr += strcspn(ptr, " "); + width = strtol(ptr, NULL, 10); + } else if (strncmp(ptr, "height", 6) == 0) { + ptr += strcspn(ptr, " "); + height = strtol(ptr, NULL, 10); + } else { + // skip offset and unknown variables + av_log(avctx, AV_LOG_VERBOSE, + "Ignoring preprocessor directive.\n"); + } + } + + if ((ret = ff_set_dimensions(avctx, width, height)) < 0) + return ret; + + if ((ret = ff_get_buffer(avctx, p, 0)) < 0) + return ret; + + // go to start of image data + ptr += strcspn(ptr, "{"); + + linesize = (avctx->width + 7) / 8; + for (i = 0; i < avctx->height; i++) { + int eol = 0, e = 0; + dst = p->data[0] + i * p->linesize[0]; + if (ptr >= avpkt->data + avpkt->size) { + av_log(avctx, AV_LOG_ERROR, "End of file reached.\n"); + return AVERROR_INVALIDDATA; + } + do { + int val; + uint8_t *endptr; + + ptr += strcspn(ptr, "x") - 1; // -1 to get 0x + val = strtol(ptr, (char **)&endptr, 16); + + if (endptr - ptr == 4) { + // XBM X11 format + *dst++ = ff_reverse[val]; + eol = linesize; + } else if (endptr - ptr == 6) { + // XBM X10 format + *dst++ = ff_reverse[val >> 8]; + *dst++ = ff_reverse[val & 0xFF]; + eol = linesize / 2; // 2 bytes read + } else { + av_log(avctx, AV_LOG_ERROR, + "Unexpected data at %.8s.\n", ptr); + return AVERROR_INVALIDDATA; + } + ptr = endptr; + } while (++e < eol); + } + + p->key_frame = 1; + p->pict_type = AV_PICTURE_TYPE_I; + + *got_frame = 1; + + return avpkt->size; +} + +AVCodec ff_xbm_decoder = { + .name = "xbm", + .long_name = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"), + .type = AVMEDIA_TYPE_VIDEO, + .id = AV_CODEC_ID_XBM, + .decode = xbm_decode_frame, + .capabilities = CODEC_CAP_DR1, +}; -- cgit v1.2.3