| /* |
| * Interplay C93 video decoder |
| * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com> |
| * |
| * 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 |
| */ |
| |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "internal.h" |
| |
| typedef struct C93DecoderContext { |
| AVFrame *pictures[2]; |
| int currentpic; |
| } C93DecoderContext; |
| |
| typedef enum { |
| C93_8X8_FROM_PREV = 0x02, |
| C93_4X4_FROM_PREV = 0x06, |
| C93_4X4_FROM_CURR = 0x07, |
| C93_8X8_2COLOR = 0x08, |
| C93_4X4_2COLOR = 0x0A, |
| C93_4X4_4COLOR_GRP = 0x0B, |
| C93_4X4_4COLOR = 0x0D, |
| C93_NOOP = 0x0E, |
| C93_8X8_INTRA = 0x0F, |
| } C93BlockType; |
| |
| #define WIDTH 320 |
| #define HEIGHT 192 |
| |
| #define C93_HAS_PALETTE 0x01 |
| #define C93_FIRST_FRAME 0x02 |
| |
| static av_cold int decode_end(AVCodecContext *avctx) |
| { |
| C93DecoderContext * const c93 = avctx->priv_data; |
| |
| av_frame_free(&c93->pictures[0]); |
| av_frame_free(&c93->pictures[1]); |
| |
| return 0; |
| } |
| |
| static av_cold int decode_init(AVCodecContext *avctx) |
| { |
| C93DecoderContext *s = avctx->priv_data; |
| avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| |
| s->pictures[0] = av_frame_alloc(); |
| s->pictures[1] = av_frame_alloc(); |
| if (!s->pictures[0] || !s->pictures[1]) { |
| decode_end(avctx); |
| return AVERROR(ENOMEM); |
| } |
| |
| return 0; |
| } |
| |
| static inline int copy_block(AVCodecContext *avctx, uint8_t *to, |
| uint8_t *from, int offset, int height, int stride) |
| { |
| int i; |
| int width = height; |
| int from_x = offset % WIDTH; |
| int from_y = offset / WIDTH; |
| int overflow = from_x + width - WIDTH; |
| |
| if (!from) { |
| /* silently ignoring predictive blocks in first frame */ |
| return 0; |
| } |
| |
| if (from_y + height > HEIGHT) { |
| av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n", |
| offset); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (overflow > 0) { |
| width -= overflow; |
| for (i = 0; i < height; i++) { |
| memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow); |
| } |
| } |
| |
| for (i = 0; i < height; i++) { |
| memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width); |
| } |
| |
| return 0; |
| } |
| |
| static inline void draw_n_color(uint8_t *out, int stride, int width, |
| int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col) |
| { |
| int x, y; |
| for (y = 0; y < height; y++) { |
| if (grps) |
| cols[0] = grps[3 * (y >> 1)]; |
| for (x = 0; x < width; x++) { |
| if (grps) |
| cols[1]= grps[(x >> 1) + 1]; |
| out[x + y*stride] = cols[col & ((1 << bpp) - 1)]; |
| col >>= bpp; |
| } |
| } |
| } |
| |
| static int decode_frame(AVCodecContext *avctx, void *data, |
| int *got_frame, AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| C93DecoderContext * const c93 = avctx->priv_data; |
| AVFrame * const newpic = c93->pictures[c93->currentpic]; |
| AVFrame * const oldpic = c93->pictures[c93->currentpic^1]; |
| GetByteContext gb; |
| uint8_t *out; |
| int stride, ret, i, x, y, b, bt = 0; |
| |
| if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0) |
| return ret; |
| |
| c93->currentpic ^= 1; |
| |
| if ((ret = ff_reget_buffer(avctx, newpic)) < 0) |
| return ret; |
| |
| stride = newpic->linesize[0]; |
| |
| bytestream2_init(&gb, buf, buf_size); |
| b = bytestream2_get_byte(&gb); |
| if (b & C93_FIRST_FRAME) { |
| newpic->pict_type = AV_PICTURE_TYPE_I; |
| newpic->key_frame = 1; |
| } else { |
| newpic->pict_type = AV_PICTURE_TYPE_P; |
| newpic->key_frame = 0; |
| } |
| |
| for (y = 0; y < HEIGHT; y += 8) { |
| out = newpic->data[0] + y * stride; |
| for (x = 0; x < WIDTH; x += 8) { |
| uint8_t *copy_from = oldpic->data[0]; |
| unsigned int offset, j; |
| uint8_t cols[4], grps[4]; |
| C93BlockType block_type; |
| |
| if (!bt) |
| bt = bytestream2_get_byte(&gb); |
| |
| block_type= bt & 0x0F; |
| switch (block_type) { |
| case C93_8X8_FROM_PREV: |
| offset = bytestream2_get_le16(&gb); |
| if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0) |
| return ret; |
| break; |
| |
| case C93_4X4_FROM_CURR: |
| copy_from = newpic->data[0]; |
| case C93_4X4_FROM_PREV: |
| for (j = 0; j < 8; j += 4) { |
| for (i = 0; i < 8; i += 4) { |
| int offset = bytestream2_get_le16(&gb); |
| int from_x = offset % WIDTH; |
| int from_y = offset / WIDTH; |
| if (block_type == C93_4X4_FROM_CURR && from_y == y+j && |
| (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) { |
| avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j); |
| return AVERROR_INVALIDDATA; |
| } |
| if ((ret = copy_block(avctx, &out[j*stride+i], |
| copy_from, offset, 4, stride)) < 0) |
| return ret; |
| } |
| } |
| break; |
| |
| case C93_8X8_2COLOR: |
| bytestream2_get_buffer(&gb, cols, 2); |
| for (i = 0; i < 8; i++) { |
| draw_n_color(out + i*stride, stride, 8, 1, 1, cols, |
| NULL, bytestream2_get_byte(&gb)); |
| } |
| |
| break; |
| |
| case C93_4X4_2COLOR: |
| case C93_4X4_4COLOR: |
| case C93_4X4_4COLOR_GRP: |
| for (j = 0; j < 8; j += 4) { |
| for (i = 0; i < 8; i += 4) { |
| if (block_type == C93_4X4_2COLOR) { |
| bytestream2_get_buffer(&gb, cols, 2); |
| draw_n_color(out + i + j*stride, stride, 4, 4, |
| 1, cols, NULL, bytestream2_get_le16(&gb)); |
| } else if (block_type == C93_4X4_4COLOR) { |
| bytestream2_get_buffer(&gb, cols, 4); |
| draw_n_color(out + i + j*stride, stride, 4, 4, |
| 2, cols, NULL, bytestream2_get_le32(&gb)); |
| } else { |
| bytestream2_get_buffer(&gb, grps, 4); |
| draw_n_color(out + i + j*stride, stride, 4, 4, |
| 1, cols, grps, bytestream2_get_le16(&gb)); |
| } |
| } |
| } |
| break; |
| |
| case C93_NOOP: |
| break; |
| |
| case C93_8X8_INTRA: |
| for (j = 0; j < 8; j++) |
| bytestream2_get_buffer(&gb, out + j*stride, 8); |
| break; |
| |
| default: |
| av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n", |
| block_type, x, y); |
| return AVERROR_INVALIDDATA; |
| } |
| bt >>= 4; |
| out += 8; |
| } |
| } |
| |
| if (b & C93_HAS_PALETTE) { |
| uint32_t *palette = (uint32_t *) newpic->data[1]; |
| for (i = 0; i < 256; i++) { |
| palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb); |
| } |
| newpic->palette_has_changed = 1; |
| } else { |
| if (oldpic->data[1]) |
| memcpy(newpic->data[1], oldpic->data[1], 256 * 4); |
| } |
| |
| if ((ret = av_frame_ref(data, newpic)) < 0) |
| return ret; |
| *got_frame = 1; |
| |
| return buf_size; |
| } |
| |
| AVCodec ff_c93_decoder = { |
| .name = "c93", |
| .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_C93, |
| .priv_data_size = sizeof(C93DecoderContext), |
| .init = decode_init, |
| .close = decode_end, |
| .decode = decode_frame, |
| .capabilities = AV_CODEC_CAP_DR1, |
| }; |
