/* * Feeble Files/ScummVM DXA decoder * Copyright (c) 2007 Konstantin Shishkov * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * DXA Video decoder */ #include "libavutil/common.h" #include "libavutil/intreadwrite.h" #include "bytestream.h" #include "avcodec.h" #include "codec_internal.h" #include "decode.h" #include <zlib.h> /* * Decoder context */ typedef struct DxaDecContext { AVFrame *prev; int dsize; #define DECOMP_BUF_PADDING 16 uint8_t *decomp_buf; uint32_t pal[256]; } DxaDecContext; static const int shift1[6] = { 0, 8, 8, 8, 4, 4 }; static const int shift2[6] = { 0, 0, 8, 4, 0, 4 }; static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst, int stride, uint8_t *src, int srcsize, uint8_t *ref) { uint8_t *code, *data, *mv, *msk, *tmp, *tmp2; uint8_t *src_end = src + srcsize; int i, j, k; int type, x, y, d, d2; uint32_t mask; if (12ULL + ((avctx->width * avctx->height) >> 4) + AV_RB32(src + 0) + AV_RB32(src + 4) > srcsize) return AVERROR_INVALIDDATA; code = src + 12; data = code + ((avctx->width * avctx->height) >> 4); mv = data + AV_RB32(src + 0); msk = mv + AV_RB32(src + 4); for(j = 0; j < avctx->height; j += 4){ for(i = 0; i < avctx->width; i += 4){ if (data > src_end || mv > src_end || msk > src_end) return AVERROR_INVALIDDATA; tmp = dst + i; tmp2 = ref + i; type = *code++; switch(type){ case 4: // motion compensation x = (*mv) >> 4; if(x & 8) x = 8 - x; y = (*mv++) & 0xF; if(y & 8) y = 8 - y; if (i < -x || avctx->width - i - 4 < x || j < -y || avctx->height - j - 4 < y) { av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y); return AVERROR_INVALIDDATA; } tmp2 += x + y*stride; case 0: // skip case 5: // skip in method 12 for(y = 0; y < 4; y++){ memcpy(tmp, tmp2, 4); tmp += stride; tmp2 += stride; } break; case 1: // masked change case 10: // masked change with only half of pixels changed case 11: // cases 10-15 are for method 12 only case 12: case 13: case 14: case 15: if(type == 1){ mask = AV_RB16(msk); msk += 2; }else{ type -= 10; mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]); msk++; } for(y = 0; y < 4; y++){ for(x = 0; x < 4; x++){ tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x]; mask <<= 1; } tmp += stride; tmp2 += stride; } break; case 2: // fill block for(y = 0; y < 4; y++){ memset(tmp, data[0], 4); tmp += stride; } data++; break; case 3: // raw block for(y = 0; y < 4; y++){ memcpy(tmp, data, 4); data += 4; tmp += stride; } break; case 8: // subblocks - method 13 only mask = *msk++; for(k = 0; k < 4; k++){ d = ((k & 1) << 1) + ((k & 2) * stride); d2 = ((k & 1) << 1) + ((k & 2) * stride); tmp2 = ref + i + d2; switch(mask & 0xC0){ case 0x80: // motion compensation x = (*mv) >> 4; if(x & 8) x = 8 - x; y = (*mv++) & 0xF; if(y & 8) y = 8 - y; if (i + 2*(k & 1) < -x || avctx->width - i - 2*(k & 1) - 2 < x || j + (k & 2) < -y || avctx->height - j - (k & 2) - 2 < y) { av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y); return AVERROR_INVALIDDATA; } tmp2 += x + y*stride; case 0x00: // skip tmp[d + 0 ] = tmp2[0]; tmp[d + 1 ] = tmp2[1]; tmp[d + 0 + stride] = tmp2[0 + stride]; tmp[d + 1 + stride] = tmp2[1 + stride]; break; case 0x40: // fill tmp[d + 0 ] = data[0]; tmp[d + 1 ] = data[0]; tmp[d + 0 + stride] = data[0]; tmp[d + 1 + stride] = data[0]; data++; break; case 0xC0: // raw tmp[d + 0 ] = *data++; tmp[d + 1 ] = *data++; tmp[d + 0 + stride] = *data++; tmp[d + 1 + stride] = *data++; break; } mask <<= 2; } break; case 32: // vector quantization - 2 colors mask = AV_RB16(msk); msk += 2; for(y = 0; y < 4; y++){ for(x = 0; x < 4; x++){ tmp[x] = data[mask & 1]; mask >>= 1; } tmp += stride; tmp2 += stride; } data += 2; break; case 33: // vector quantization - 3 or 4 colors case 34: mask = AV_RB32(msk); msk += 4; for(y = 0; y < 4; y++){ for(x = 0; x < 4; x++){ tmp[x] = data[mask & 3]; mask >>= 2; } tmp += stride; tmp2 += stride; } data += type - 30; break; default: av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type); return AVERROR_INVALIDDATA; } } dst += stride * 4; ref += stride * 4; } return 0; } static int decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt) { DxaDecContext * const c = avctx->priv_data; uint8_t *outptr, *srcptr, *tmpptr; unsigned long dsize; int i, j, compr, ret; int stride; int pc = 0; GetByteContext gb; bytestream2_init(&gb, avpkt->data, avpkt->size); /* make the palette available on the way out */ if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) { bytestream2_skip(&gb, 4); for(i = 0; i < 256; i++){ c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb); } pc = 1; } if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) return ret; memcpy(frame->data[1], c->pal, AVPALETTE_SIZE); frame->palette_has_changed = pc; outptr = frame->data[0]; srcptr = c->decomp_buf; tmpptr = c->prev->data[0]; stride = frame->linesize[0]; if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L')) compr = -1; else compr = bytestream2_get_byte(&gb); dsize = c->dsize; if (compr != 4 && compr != -1) { bytestream2_skip(&gb, 4); if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb), bytestream2_get_bytes_left(&gb)) != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n"); return AVERROR_UNKNOWN; } memset(c->decomp_buf + dsize, 0, DECOMP_BUF_PADDING); } if (avctx->debug & FF_DEBUG_PICT_INFO) av_log(avctx, AV_LOG_DEBUG, "compr:%2d, dsize:%d\n", compr, (int)dsize); switch(compr){ case -1: frame->key_frame = 0; frame->pict_type = AV_PICTURE_TYPE_P; if (c->prev->data[0]) memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height); else{ // Should happen only when first frame is 'NULL' memset(frame->data[0], 0, frame->linesize[0] * avctx->height); frame->key_frame = 1; frame->pict_type = AV_PICTURE_TYPE_I; } break; case 2: case 4: frame->key_frame = 1; frame->pict_type = AV_PICTURE_TYPE_I; for (j = 0; j < avctx->height; j++) { memcpy(outptr, srcptr, avctx->width); outptr += stride; srcptr += avctx->width; } break; case 3: case 5: if (!tmpptr) { av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n"); if (!(avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL)) return AVERROR_INVALIDDATA; } frame->key_frame = 0; frame->pict_type = AV_PICTURE_TYPE_P; for (j = 0; j < avctx->height; j++) { if(tmpptr){ for(i = 0; i < avctx->width; i++) outptr[i] = srcptr[i] ^ tmpptr[i]; tmpptr += stride; }else memcpy(outptr, srcptr, avctx->width); outptr += stride; srcptr += avctx->width; } break; case 12: // ScummVM coding case 13: frame->key_frame = 0; frame->pict_type = AV_PICTURE_TYPE_P; if (!c->prev->data[0]) { av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n"); return AVERROR_INVALIDDATA; } decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, dsize, c->prev->data[0]); break; default: av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr); return AVERROR_INVALIDDATA; } av_frame_unref(c->prev); if ((ret = av_frame_ref(c->prev, frame)) < 0) return ret; *got_frame = 1; /* always report that the buffer was completely consumed */ return avpkt->size; } static av_cold int decode_init(AVCodecContext *avctx) { DxaDecContext * const c = avctx->priv_data; if (avctx->width%4 || avctx->height%4) { avpriv_request_sample(avctx, "dimensions are not a multiple of 4"); return AVERROR_INVALIDDATA; } c->prev = av_frame_alloc(); if (!c->prev) return AVERROR(ENOMEM); avctx->pix_fmt = AV_PIX_FMT_PAL8; c->dsize = avctx->width * avctx->height * 2; c->decomp_buf = av_malloc(c->dsize + DECOMP_BUF_PADDING); if (!c->decomp_buf) { av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); return AVERROR(ENOMEM); } return 0; } static av_cold int decode_end(AVCodecContext *avctx) { DxaDecContext * const c = avctx->priv_data; av_freep(&c->decomp_buf); av_frame_free(&c->prev); return 0; } const FFCodec ff_dxa_decoder = { .p.name = "dxa", CODEC_LONG_NAME("Feeble Files/ScummVM DXA"), .p.type = AVMEDIA_TYPE_VIDEO, .p.id = AV_CODEC_ID_DXA, .priv_data_size = sizeof(DxaDecContext), .init = decode_init, .close = decode_end, FF_CODEC_DECODE_CB(decode_frame), .p.capabilities = AV_CODEC_CAP_DR1, .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, };