static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { PCXContext * const s = avctx->priv_data; AVFrame *picture = data; AVFrame * const p = &s->picture; GetByteContext gb; int compressed, xmin, ymin, xmax, ymax, ret; unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x, bytes_per_scanline; uint8_t *ptr, *scanline; if (avpkt->size < 128) return AVERROR_INVALIDDATA; bytestream2_init(&gb, avpkt->data, avpkt->size); if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) { av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n"); return AVERROR_INVALIDDATA; } compressed = bytestream2_get_byteu(&gb); bits_per_pixel = bytestream2_get_byteu(&gb); xmin = bytestream2_get_le16u(&gb); ymin = bytestream2_get_le16u(&gb); xmax = bytestream2_get_le16u(&gb); ymax = bytestream2_get_le16u(&gb); avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb); avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb); 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; bytestream2_skipu(&gb, 49); nplanes = bytestream2_get_byteu(&gb); bytes_per_line = bytestream2_get_le16u(&gb); bytes_per_scanline = nplanes * bytes_per_line; if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8) { 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; } bytestream2_skipu(&gb, 60); if (p->data[0]) avctx->release_buffer(avctx, p); if ((ret = av_image_check_size(w, h, 0, avctx)) < 0) return ret; if (w != avctx->width || h != avctx->height) avcodec_set_dimensions(avctx, w, h); if ((ret = ff_get_buffer(avctx, p)) < 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++) { pcx_rle_decode(&gb, 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) { int palstart = avpkt->size - 769; for (y=0; y<h; y++, ptr+=stride) { pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed); memcpy(ptr, scanline, w); } if (bytestream2_tell(&gb) != palstart) { av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n"); bytestream2_seek(&gb, palstart, SEEK_SET); } if (bytestream2_get_byte(&gb) != 12) { av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n"); ret = AVERROR_INVALIDDATA; goto end; } } else if (nplanes == 1) { /* all packed formats, max. 16 colors */ GetBitContext s; for (y=0; y<h; y++) { init_get_bits8(&s, scanline, bytes_per_scanline); pcx_rle_decode(&gb, 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++) { pcx_rle_decode(&gb, 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; } } ret = bytestream2_tell(&gb); if (nplanes == 1 && bits_per_pixel == 8) { pcx_palette(&gb, (uint32_t *) p->data[1], 256); ret += 256 * 3; } else if (bits_per_pixel * nplanes == 1) { AV_WN32A(p->data[1] , 0xFF000000); AV_WN32A(p->data[1]+4, 0xFFFFFFFF); } else if (bits_per_pixel < 8) { bytestream2_seek(&gb, 16, SEEK_SET); pcx_palette(&gb, (uint32_t *) p->data[1], 16); } *picture = s->picture; *got_frame = 1; end: av_free(scanline); return ret; }