| /* |
| * CDToons video decoder |
| * Copyright (C) 2020 Alyssa Milburn <amilburn@zall.org> |
| * |
| * 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 |
| * CDToons video decoder |
| * @author Alyssa Milburn <amilburn@zall.org> |
| */ |
| |
| #include <stdint.h> |
| |
| #include "libavutil/attributes.h" |
| #include "libavutil/internal.h" |
| #include "avcodec.h" |
| #include "bytestream.h" |
| #include "internal.h" |
| |
| #define CDTOONS_HEADER_SIZE 44 |
| #define CDTOONS_MAX_SPRITES 1200 |
| |
| typedef struct CDToonsSprite { |
| uint16_t flags; |
| uint16_t owner_frame; |
| uint16_t start_frame; |
| uint16_t end_frame; |
| unsigned int alloc_size; |
| uint32_t size; |
| uint8_t *data; |
| int active; |
| } CDToonsSprite; |
| |
| typedef struct CDToonsContext { |
| AVFrame *frame; |
| |
| uint16_t last_pal_id; ///< The index of the active palette sprite. |
| uint32_t pal[256]; ///< The currently-used palette data. |
| CDToonsSprite sprites[CDTOONS_MAX_SPRITES]; |
| } CDToonsContext; |
| |
| static int cdtoons_render_sprite(AVCodecContext *avctx, const uint8_t *data, |
| uint32_t data_size, |
| int dst_x, int dst_y, int width, int height) |
| { |
| CDToonsContext *c = avctx->priv_data; |
| const uint8_t *next_line = data; |
| const uint8_t *end = data + data_size; |
| uint16_t line_size; |
| uint8_t *dest; |
| int skip = 0, to_skip, x; |
| |
| if (dst_x + width > avctx->width) |
| width = avctx->width - dst_x; |
| if (dst_y + height > avctx->height) |
| height = avctx->height - dst_y; |
| |
| if (dst_x < 0) { |
| /* we need to skip the start of the scanlines */ |
| skip = -dst_x; |
| if (width <= skip) |
| return 0; |
| dst_x = 0; |
| } |
| |
| for (int y = 0; y < height; y++) { |
| /* one scanline at a time, size is provided */ |
| data = next_line; |
| if (end - data < 2) |
| return 1; |
| line_size = bytestream_get_be16(&data); |
| if (end - data < line_size) |
| return 1; |
| next_line = data + line_size; |
| if (dst_y + y < 0) |
| continue; |
| |
| dest = c->frame->data[0] + (dst_y + y) * c->frame->linesize[0] + dst_x; |
| |
| to_skip = skip; |
| x = 0; |
| while (x < width - skip) { |
| int raw, size, step; |
| uint8_t val; |
| |
| if (data >= end) |
| return 1; |
| |
| val = bytestream_get_byte(&data); |
| raw = !(val & 0x80); |
| size = (int)(val & 0x7F) + 1; |
| |
| /* skip the start of a scanline if it is off-screen */ |
| if (to_skip >= size) { |
| to_skip -= size; |
| if (raw) { |
| step = size; |
| } else { |
| step = 1; |
| } |
| if (next_line - data < step) |
| return 1; |
| data += step; |
| continue; |
| } else if (to_skip) { |
| size -= to_skip; |
| if (raw) { |
| if (next_line - data < to_skip) |
| return 1; |
| data += to_skip; |
| } |
| to_skip = 0; |
| } |
| |
| if (x + size >= width - skip) |
| size = width - skip - x; |
| |
| /* either raw data, or a run of a single color */ |
| if (raw) { |
| if (next_line - data < size) |
| return 1; |
| memcpy(dest + x, data, size); |
| data += size; |
| } else { |
| uint8_t color = bytestream_get_byte(&data); |
| /* ignore transparent runs */ |
| if (color) |
| memset(dest + x, color, size); |
| } |
| x += size; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int cdtoons_decode_frame(AVCodecContext *avctx, void *data, |
| int *got_frame, AVPacket *avpkt) |
| { |
| CDToonsContext *c = avctx->priv_data; |
| const uint8_t *buf = avpkt->data; |
| const uint8_t *eod = avpkt->data + avpkt->size; |
| const int buf_size = avpkt->size; |
| uint16_t frame_id; |
| uint8_t background_color; |
| uint16_t sprite_count, sprite_offset; |
| uint8_t referenced_count; |
| uint16_t palette_id; |
| uint8_t palette_set; |
| int ret; |
| int saw_embedded_sprites = 0; |
| |
| if (buf_size < CDTOONS_HEADER_SIZE) |
| return AVERROR_INVALIDDATA; |
| |
| if ((ret = ff_reget_buffer(avctx, c->frame, 0)) < 0) |
| return ret; |
| |
| /* a lot of the header is useless junk in the absence of |
| * dirty rectangling etc */ |
| buf += 2; /* version? (always 9?) */ |
| frame_id = bytestream_get_be16(&buf); |
| buf += 2; /* blocks_valid_until */ |
| buf += 1; |
| background_color = bytestream_get_byte(&buf); |
| buf += 16; /* clip rect, dirty rect */ |
| buf += 4; /* flags */ |
| sprite_count = bytestream_get_be16(&buf); |
| sprite_offset = bytestream_get_be16(&buf); |
| buf += 2; /* max block id? */ |
| referenced_count = bytestream_get_byte(&buf); |
| buf += 1; |
| palette_id = bytestream_get_be16(&buf); |
| palette_set = bytestream_get_byte(&buf); |
| buf += 5; |
| |
| if (sprite_offset > buf_size) |
| return AVERROR_INVALIDDATA; |
| |
| /* read new sprites introduced in this frame */ |
| buf = avpkt->data + sprite_offset; |
| while (sprite_count--) { |
| uint32_t size; |
| uint16_t sprite_id; |
| |
| if (buf + 14 > eod) |
| return AVERROR_INVALIDDATA; |
| |
| sprite_id = bytestream_get_be16(&buf); |
| if (sprite_id >= CDTOONS_MAX_SPRITES) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Sprite ID %d is too high.\n", sprite_id); |
| return AVERROR_INVALIDDATA; |
| } |
| if (c->sprites[sprite_id].active) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Sprite ID %d is a duplicate.\n", sprite_id); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| c->sprites[sprite_id].flags = bytestream_get_be16(&buf); |
| size = bytestream_get_be32(&buf); |
| if (size < 14) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Sprite only has %d bytes of data.\n", size); |
| return AVERROR_INVALIDDATA; |
| } |
| size -= 14; |
| c->sprites[sprite_id].size = size; |
| c->sprites[sprite_id].owner_frame = frame_id; |
| c->sprites[sprite_id].start_frame = bytestream_get_be16(&buf); |
| c->sprites[sprite_id].end_frame = bytestream_get_be16(&buf); |
| buf += 2; |
| |
| if (size > buf_size || buf + size > eod) |
| return AVERROR_INVALIDDATA; |
| |
| av_fast_padded_malloc(&c->sprites[sprite_id].data, &c->sprites[sprite_id].alloc_size, size); |
| if (!c->sprites[sprite_id].data) |
| return AVERROR(ENOMEM); |
| |
| c->sprites[sprite_id].active = 1; |
| |
| bytestream_get_buffer(&buf, c->sprites[sprite_id].data, size); |
| } |
| |
| /* render any embedded sprites */ |
| while (buf < eod) { |
| uint32_t tag, size; |
| if (buf + 8 > eod) { |
| av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for embedded sprites.\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| tag = bytestream_get_be32(&buf); |
| size = bytestream_get_be32(&buf); |
| if (tag == MKBETAG('D', 'i', 'f', 'f')) { |
| uint16_t diff_count; |
| if (buf + 10 > eod) { |
| av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame.\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| diff_count = bytestream_get_be16(&buf); |
| buf += 8; /* clip rect? */ |
| for (int i = 0; i < diff_count; i++) { |
| int16_t top, left; |
| uint16_t diff_size, width, height; |
| |
| if (buf + 16 > eod) { |
| av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame header.\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| top = bytestream_get_be16(&buf); |
| left = bytestream_get_be16(&buf); |
| buf += 4; /* bottom, right */ |
| diff_size = bytestream_get_be32(&buf); |
| width = bytestream_get_be16(&buf); |
| height = bytestream_get_be16(&buf); |
| if (diff_size < 8 || diff_size - 4 > eod - buf) { |
| av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame data.\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| if (cdtoons_render_sprite(avctx, buf + 4, diff_size - 8, |
| left, top, width, height)) { |
| av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n"); |
| } |
| buf += diff_size - 4; |
| } |
| saw_embedded_sprites = 1; |
| } else { |
| /* we don't care about any other entries */ |
| if (size < 8 || size - 8 > eod - buf) { |
| av_log(avctx, AV_LOG_WARNING, "Ran out of data for ignored entry (size %X, %d left).\n", size, (int)(eod - buf)); |
| return AVERROR_INVALIDDATA; |
| } |
| buf += (size - 8); |
| } |
| } |
| |
| /* was an intra frame? */ |
| if (saw_embedded_sprites) |
| goto done; |
| |
| /* render any referenced sprites */ |
| buf = avpkt->data + CDTOONS_HEADER_SIZE; |
| eod = avpkt->data + sprite_offset; |
| for (int i = 0; i < referenced_count; i++) { |
| const uint8_t *block_data; |
| uint16_t sprite_id, width, height; |
| int16_t top, left, right; |
| |
| if (buf + 10 > eod) { |
| av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data when rendering.\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| sprite_id = bytestream_get_be16(&buf); |
| top = bytestream_get_be16(&buf); |
| left = bytestream_get_be16(&buf); |
| buf += 2; /* bottom */ |
| right = bytestream_get_be16(&buf); |
| |
| if ((i == 0) && (sprite_id == 0)) { |
| /* clear background */ |
| memset(c->frame->data[0], background_color, |
| c->frame->linesize[0] * avctx->height); |
| } |
| |
| if (!right) |
| continue; |
| if (sprite_id >= CDTOONS_MAX_SPRITES) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Sprite ID %d is too high.\n", sprite_id); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| block_data = c->sprites[sprite_id].data; |
| if (!c->sprites[sprite_id].active) { |
| /* this can happen when seeking around */ |
| av_log(avctx, AV_LOG_WARNING, "Sprite %d is missing.\n", sprite_id); |
| continue; |
| } |
| if (c->sprites[sprite_id].size < 14) { |
| av_log(avctx, AV_LOG_ERROR, "Sprite %d is too small.\n", sprite_id); |
| continue; |
| } |
| |
| height = bytestream_get_be16(&block_data); |
| width = bytestream_get_be16(&block_data); |
| block_data += 10; |
| if (cdtoons_render_sprite(avctx, block_data, |
| c->sprites[sprite_id].size - 14, |
| left, top, width, height)) { |
| av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n"); |
| } |
| } |
| |
| if (palette_id && (palette_id != c->last_pal_id)) { |
| if (palette_id >= CDTOONS_MAX_SPRITES) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Palette ID %d is too high.\n", palette_id); |
| return AVERROR_INVALIDDATA; |
| } |
| if (!c->sprites[palette_id].active) { |
| /* this can happen when seeking around */ |
| av_log(avctx, AV_LOG_WARNING, |
| "Palette ID %d is missing.\n", palette_id); |
| goto done; |
| } |
| if (c->sprites[palette_id].size != 256 * 2 * 3) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Palette ID %d is wrong size (%d).\n", |
| palette_id, c->sprites[palette_id].size); |
| return AVERROR_INVALIDDATA; |
| } |
| c->last_pal_id = palette_id; |
| if (!palette_set) { |
| uint8_t *palette_data = c->sprites[palette_id].data; |
| for (int i = 0; i < 256; i++) { |
| /* QuickTime-ish palette: 16-bit RGB components */ |
| unsigned r, g, b; |
| r = *palette_data; |
| g = *(palette_data + 2); |
| b = *(palette_data + 4); |
| c->pal[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b; |
| palette_data += 6; |
| } |
| /* first palette entry indicates transparency */ |
| c->pal[0] = 0; |
| c->frame->palette_has_changed = 1; |
| } |
| } |
| |
| done: |
| /* discard outdated blocks */ |
| for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) { |
| if (c->sprites[i].end_frame > frame_id) |
| continue; |
| c->sprites[i].active = 0; |
| } |
| |
| memcpy(c->frame->data[1], c->pal, AVPALETTE_SIZE); |
| |
| if ((ret = av_frame_ref(data, c->frame)) < 0) |
| return ret; |
| |
| *got_frame = 1; |
| |
| /* always report that the buffer was completely consumed */ |
| return buf_size; |
| } |
| |
| static av_cold int cdtoons_decode_init(AVCodecContext *avctx) |
| { |
| CDToonsContext *c = avctx->priv_data; |
| |
| avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| c->last_pal_id = 0; |
| c->frame = av_frame_alloc(); |
| if (!c->frame) |
| return AVERROR(ENOMEM); |
| |
| return 0; |
| } |
| |
| static void cdtoons_flush(AVCodecContext *avctx) |
| { |
| CDToonsContext *c = avctx->priv_data; |
| |
| c->last_pal_id = 0; |
| for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) |
| c->sprites[i].active = 0; |
| } |
| |
| static av_cold int cdtoons_decode_end(AVCodecContext *avctx) |
| { |
| CDToonsContext *c = avctx->priv_data; |
| |
| for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) { |
| av_freep(&c->sprites[i].data); |
| c->sprites[i].active = 0; |
| } |
| |
| av_frame_free(&c->frame); |
| |
| return 0; |
| } |
| |
| AVCodec ff_cdtoons_decoder = { |
| .name = "cdtoons", |
| .long_name = NULL_IF_CONFIG_SMALL("CDToons video"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_CDTOONS, |
| .priv_data_size = sizeof(CDToonsContext), |
| .init = cdtoons_decode_init, |
| .close = cdtoons_decode_end, |
| .decode = cdtoons_decode_frame, |
| .capabilities = AV_CODEC_CAP_DR1, |
| .flush = cdtoons_flush, |
| .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, |
| }; |