xref: /third_party/ffmpeg/libavcodec/anm.c (revision cabdff1a)
1/*
2 * Deluxe Paint Animation decoder
3 * Copyright (c) 2009 Peter Ross
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * Deluxe Paint Animation decoder
25 */
26
27#include "avcodec.h"
28#include "bytestream.h"
29#include "codec_internal.h"
30#include "internal.h"
31
32typedef struct AnmContext {
33    AVFrame *frame;
34    int palette[AVPALETTE_COUNT];
35} AnmContext;
36
37static av_cold int decode_init(AVCodecContext *avctx)
38{
39    AnmContext *s = avctx->priv_data;
40    GetByteContext gb;
41    int i;
42
43    if (avctx->extradata_size < 16 * 8 + 4 * 256)
44        return AVERROR_INVALIDDATA;
45
46    avctx->pix_fmt = AV_PIX_FMT_PAL8;
47
48    s->frame = av_frame_alloc();
49    if (!s->frame)
50        return AVERROR(ENOMEM);
51
52    bytestream2_init(&gb, avctx->extradata, avctx->extradata_size);
53    bytestream2_skipu(&gb, 16 * 8);
54    for (i = 0; i < 256; i++)
55        s->palette[i] = (0xFFU << 24) | bytestream2_get_le32u(&gb);
56
57    return 0;
58}
59
60/**
61 * Perform decode operation
62 * @param dst     pointer to destination image buffer
63 * @param dst_end pointer to end of destination image buffer
64 * @param gb GetByteContext (optional, see below)
65 * @param pixel Fill color (optional, see below)
66 * @param count Pixel count
67 * @param x Pointer to x-axis counter
68 * @param width Image width
69 * @param linesize Destination image buffer linesize
70 * @return non-zero if destination buffer is exhausted
71 *
72 * a copy operation is achieved when 'gb' is set
73 * a fill operation is achieved when 'gb' is null and pixel is >= 0
74 * a skip operation is achieved when 'gb' is null and pixel is < 0
75 */
76static inline int op(uint8_t **dst, const uint8_t *dst_end,
77                     GetByteContext *gb,
78                     int pixel, int count,
79                     int *x, int width, int linesize)
80{
81    int remaining = width - *x;
82    while(count > 0) {
83        int striplen = FFMIN(count, remaining);
84        if (gb) {
85            if (bytestream2_get_bytes_left(gb) < striplen)
86                goto exhausted;
87            bytestream2_get_bufferu(gb, *dst, striplen);
88        } else if (pixel >= 0)
89            memset(*dst, pixel, striplen);
90        *dst      += striplen;
91        remaining -= striplen;
92        count     -= striplen;
93        if (remaining <= 0) {
94            *dst      += linesize - width;
95            remaining  = width;
96        }
97        if (linesize > 0) {
98            if (*dst >= dst_end) goto exhausted;
99        } else {
100            if (*dst <= dst_end) goto exhausted;
101        }
102    }
103    *x = width - remaining;
104    return 0;
105
106exhausted:
107    *x = width - remaining;
108    return 1;
109}
110
111static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
112                        int *got_frame, AVPacket *avpkt)
113{
114    AnmContext *s = avctx->priv_data;
115    const int buf_size = avpkt->size;
116    uint8_t *dst, *dst_end;
117    GetByteContext gb;
118    int count, ret, x = 0;
119
120    if (buf_size < 7)
121        return AVERROR_INVALIDDATA;
122
123    if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
124        return ret;
125    dst     = s->frame->data[0];
126    dst_end = s->frame->data[0] + s->frame->linesize[0]*avctx->height;
127
128    bytestream2_init(&gb, avpkt->data, buf_size);
129
130    if (bytestream2_get_byte(&gb) != 0x42) {
131        avpriv_request_sample(avctx, "Unknown record type");
132        return AVERROR_INVALIDDATA;
133    }
134    if (bytestream2_get_byte(&gb)) {
135        avpriv_request_sample(avctx, "Padding bytes");
136        return AVERROR_PATCHWELCOME;
137    }
138    bytestream2_skip(&gb, 2);
139
140    do {
141        /* if statements are ordered by probability */
142#define OP(gb, pixel, count) \
143    op(&dst, dst_end, (gb), (pixel), (count), &x, avctx->width, s->frame->linesize[0])
144
145        int type = bytestream2_get_byte(&gb);
146        count = type & 0x7F;
147        type >>= 7;
148        if (count) {
149            if (OP(type ? NULL : &gb, -1, count)) break;
150        } else if (!type) {
151            int pixel;
152            count = bytestream2_get_byte(&gb);  /* count==0 gives nop */
153            pixel = bytestream2_get_byte(&gb);
154            if (OP(NULL, pixel, count)) break;
155        } else {
156            int pixel;
157            type = bytestream2_get_le16(&gb);
158            count = type & 0x3FFF;
159            type >>= 14;
160            if (!count) {
161                if (type == 0)
162                    break; // stop
163                if (type == 2) {
164                    avpriv_request_sample(avctx, "Unknown opcode");
165                    return AVERROR_PATCHWELCOME;
166                }
167                continue;
168            }
169            pixel = type == 3 ? bytestream2_get_byte(&gb) : -1;
170            if (type == 1) count += 0x4000;
171            if (OP(type == 2 ? &gb : NULL, pixel, count)) break;
172        }
173    } while (bytestream2_get_bytes_left(&gb) > 0);
174
175    memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
176
177    *got_frame = 1;
178    if ((ret = av_frame_ref(rframe, s->frame)) < 0)
179        return ret;
180
181    return buf_size;
182}
183
184static av_cold int decode_end(AVCodecContext *avctx)
185{
186    AnmContext *s = avctx->priv_data;
187
188    av_frame_free(&s->frame);
189    return 0;
190}
191
192const FFCodec ff_anm_decoder = {
193    .p.name         = "anm",
194    .p.long_name    = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
195    .p.type         = AVMEDIA_TYPE_VIDEO,
196    .p.id           = AV_CODEC_ID_ANM,
197    .priv_data_size = sizeof(AnmContext),
198    .init           = decode_init,
199    .close          = decode_end,
200    FF_CODEC_DECODE_CB(decode_frame),
201    .p.capabilities = AV_CODEC_CAP_DR1,
202    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
203};
204