/* * PC Paintbrush PCX (.pcx) image decoder * Copyright (c) 2007, 2008 Ivo van Poorten * * This decoder does not support CGA palettes. I am unable to find samples * and Netpbm cannot generate them. * * 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/imgutils.h" #include "avcodec.h" #include "bytestream.h" #include "get_bits.h" #include "internal.h" /** * @return advanced src pointer */ static const uint8_t *pcx_rle_decode(const uint8_t *src, const uint8_t *end, uint8_t *dst, unsigned int bytes_per_scanline, int compressed) { unsigned int i = 0; unsigned char run, value; if (compressed) { while (i < bytes_per_scanline && src < end) { run = 1; value = *src++; if (value >= 0xc0 && src < end) { run = value & 0x3f; value = *src++; } while (i < bytes_per_scanline && run--) dst[i++] = value; } } else { memcpy(dst, src, bytes_per_scanline); src += bytes_per_scanline; } return src; } static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) { unsigned int i; for (i = 0; i < pallen; i++) *dst++ = bytestream_get_be24(src); if (pallen < 256) memset(dst, 0, (256 - pallen) * sizeof(*dst)); } static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; AVFrame *const p = data; int compressed, xmin, ymin, xmax, ymax; unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x, bytes_per_scanline; uint8_t *ptr; const uint8_t *buf_end = buf + buf_size; const uint8_t *bufstart = buf; uint8_t *scanline; int ret = -1; if (buf[0] != 0x0a || buf[1] > 5) { av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n"); return AVERROR_INVALIDDATA; } compressed = buf[2]; xmin = AV_RL16(buf + 4); ymin = AV_RL16(buf + 6); xmax = AV_RL16(buf + 8); ymax = AV_RL16(buf + 10); if (xmax < xmin || ymax < ymin) { av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n"); return AVERROR_INVALIDDATA; } w = xmax - xmin + 1; h = ymax - ymin + 1; bits_per_pixel = buf[3]; bytes_per_line = AV_RL16(buf + 66); nplanes = buf[65]; bytes_per_scanline = nplanes * bytes_per_line; if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 || (!compressed && bytes_per_scanline > buf_size / h)) { av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n"); return AVERROR_INVALIDDATA; } switch ((nplanes << 8) + bits_per_pixel) { case 0x0308: avctx->pix_fmt = AV_PIX_FMT_RGB24; break; case 0x0108: case 0x0104: case 0x0102: case 0x0101: case 0x0401: case 0x0301: case 0x0201: avctx->pix_fmt = AV_PIX_FMT_PAL8; break; default: av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n"); return AVERROR_INVALIDDATA; } buf += 128; if ((ret = ff_set_dimensions(avctx, w, h)) < 0) return ret; if ((ret = ff_get_buffer(avctx, p, 0)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } p->pict_type = AV_PICTURE_TYPE_I; ptr = p->data[0]; stride = p->linesize[0]; scanline = av_malloc(bytes_per_scanline); if (!scanline) return AVERROR(ENOMEM); if (nplanes == 3 && bits_per_pixel == 8) { for (y = 0; y < h; y++) { buf = pcx_rle_decode(buf, buf_end, scanline, bytes_per_scanline, compressed); for (x = 0; x < w; x++) { ptr[3 * x] = scanline[x]; ptr[3 * x + 1] = scanline[x + bytes_per_line]; ptr[3 * x + 2] = scanline[x + (bytes_per_line << 1)]; } ptr += stride; } } else if (nplanes == 1 && bits_per_pixel == 8) { const uint8_t *palstart = bufstart + buf_size - 769; if (buf_size < 769) { av_log(avctx, AV_LOG_ERROR, "File is too short\n"); ret = avctx->err_recognition & AV_EF_EXPLODE ? AVERROR_INVALIDDATA : buf_size; goto end; } for (y = 0; y < h; y++, ptr += stride) { buf = pcx_rle_decode(buf, buf_end, scanline, bytes_per_scanline, compressed); memcpy(ptr, scanline, w); } if (buf != palstart) { av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n"); buf = palstart; } if (*buf++ != 12) { av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n"); ret = avctx->err_recognition & AV_EF_EXPLODE ? AVERROR_INVALIDDATA : buf_size; goto end; } } else if (nplanes == 1) { /* all packed formats, max. 16 colors */ GetBitContext s; for (y = 0; y < h; y++) { init_get_bits(&s, scanline, bytes_per_scanline << 3); buf = pcx_rle_decode(buf, buf_end, scanline, bytes_per_scanline, compressed); for (x = 0; x < w; x++) ptr[x] = get_bits(&s, bits_per_pixel); ptr += stride; } } else { /* planar, 4, 8 or 16 colors */ int i; for (y = 0; y < h; y++) { buf = pcx_rle_decode(buf, buf_end, scanline, bytes_per_scanline, compressed); for (x = 0; x < w; x++) { int m = 0x80 >> (x & 7), v = 0; for (i = nplanes - 1; i >= 0; i--) { v <<= 1; v += !!(scanline[i * bytes_per_line + (x >> 3)] & m); } ptr[x] = v; } ptr += stride; } } if (nplanes == 1 && bits_per_pixel == 8) { pcx_palette(&buf, (uint32_t *)p->data[1], 256); } else if (bits_per_pixel < 8) { const uint8_t *palette = bufstart + 16; pcx_palette(&palette, (uint32_t *)p->data[1], 16); } *got_frame = 1; ret = buf - bufstart; end: av_free(scanline); return ret; } AVCodec ff_pcx_decoder = { .name = "pcx", .long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_PCX, .decode = pcx_decode_frame, .capabilities = AV_CODEC_CAP_DR1, };