1 /*
2 * Copyright (c) 2021 Paul B Mahol
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "libavutil/common.h"
22 #include "avcodec.h"
23 #include "bytestream.h"
24 #include "codec_internal.h"
25 #include "decode.h"
26 #include "internal.h"
27
28 typedef struct SimbiosisIMXContext {
29 AVFrame *frame;
30 uint32_t pal[256];
31 uint8_t history[32768];
32 int pos;
33 } SimbiosisIMXContext;
34
imx_decode_init(AVCodecContext *avctx)35 static av_cold int imx_decode_init(AVCodecContext *avctx)
36 {
37 SimbiosisIMXContext *imx = avctx->priv_data;
38
39 avctx->pix_fmt = AV_PIX_FMT_PAL8;
40 avctx->width = 320;
41 avctx->height = 160;
42
43 imx->frame = av_frame_alloc();
44 if (!imx->frame)
45 return AVERROR(ENOMEM);
46
47 return 0;
48 }
49
imx_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)50 static int imx_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
51 int *got_frame, AVPacket *avpkt)
52 {
53 SimbiosisIMXContext *imx = avctx->priv_data;
54 int ret, x, y;
55 AVFrame *frame = imx->frame;
56 GetByteContext gb;
57
58 if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
59 return ret;
60
61 if (ff_copy_palette(imx->pal, avpkt, avctx)) {
62 frame->palette_has_changed = 1;
63 frame->key_frame = 1;
64 } else {
65 frame->key_frame = 0;
66 frame->palette_has_changed = 0;
67 }
68
69 bytestream2_init(&gb, avpkt->data, avpkt->size);
70
71 memcpy(frame->data[1], imx->pal, AVPALETTE_SIZE);
72
73 x = 0, y = 0;
74 while (bytestream2_get_bytes_left(&gb) > 0 &&
75 x < 320 && y < 160) {
76 int b = bytestream2_get_byte(&gb);
77 int len = b & 0x3f;
78 int op = b >> 6;
79 int fill;
80
81 switch (op) {
82 case 3:
83 len = len * 64 + bytestream2_get_byte(&gb);
84 case 0:
85 while (len > 0) {
86 x++;
87 len--;
88 if (x >= 320) {
89 x = 0;
90 y++;
91 }
92 if (y >= 160)
93 break;
94 }
95
96 frame->key_frame = 0;
97 break;
98 case 1:
99 if (len == 0) {
100 int offset = bytestream2_get_le16(&gb);
101
102 if (offset < 0 || offset >= 32768)
103 return AVERROR_INVALIDDATA;
104
105 len = bytestream2_get_byte(&gb);
106 while (len > 0 && offset < 32768) {
107 frame->data[0][x + y * frame->linesize[0]] = imx->history[offset++];
108 x++;
109 len--;
110 if (x >= 320) {
111 x = 0;
112 y++;
113 }
114 if (y >= 160)
115 break;
116 }
117
118 frame->key_frame = 0;
119 } else {
120 while (len > 0) {
121 fill = bytestream2_get_byte(&gb);
122 frame->data[0][x + y * frame->linesize[0]] = fill;
123 if (imx->pos < 32768)
124 imx->history[imx->pos++] = fill;
125 x++;
126 len--;
127 if (x >= 320) {
128 x = 0;
129 y++;
130 }
131 if (y >= 160)
132 break;
133 }
134 }
135 break;
136 case 2:
137 fill = bytestream2_get_byte(&gb);
138
139 while (len > 0) {
140 frame->data[0][x + y * frame->linesize[0]] = fill;
141 x++;
142 len--;
143 if (x >= 320) {
144 x = 0;
145 y++;
146 }
147 if (y >= 160)
148 break;
149 }
150 break;
151 }
152 }
153
154 frame->pict_type = frame->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
155
156 if ((ret = av_frame_ref(rframe, frame)) < 0)
157 return ret;
158
159 *got_frame = 1;
160
161 return avpkt->size;
162 }
163
imx_decode_flush(AVCodecContext *avctx)164 static void imx_decode_flush(AVCodecContext *avctx)
165 {
166 SimbiosisIMXContext *imx = avctx->priv_data;
167
168 av_frame_unref(imx->frame);
169 imx->pos = 0;
170 memset(imx->pal, 0, sizeof(imx->pal));
171 memset(imx->history, 0, sizeof(imx->history));
172 }
173
imx_decode_close(AVCodecContext *avctx)174 static int imx_decode_close(AVCodecContext *avctx)
175 {
176 SimbiosisIMXContext *imx = avctx->priv_data;
177
178 av_frame_free(&imx->frame);
179
180 return 0;
181 }
182
183 const FFCodec ff_simbiosis_imx_decoder = {
184 .p.name = "simbiosis_imx",
185 .p.long_name = NULL_IF_CONFIG_SMALL("Simbiosis Interactive IMX Video"),
186 .p.type = AVMEDIA_TYPE_VIDEO,
187 .p.id = AV_CODEC_ID_SIMBIOSIS_IMX,
188 .priv_data_size = sizeof(SimbiosisIMXContext),
189 .init = imx_decode_init,
190 FF_CODEC_DECODE_CB(imx_decode_frame),
191 .close = imx_decode_close,
192 .flush = imx_decode_flush,
193 .p.capabilities = AV_CODEC_CAP_DR1,
194 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
195 FF_CODEC_CAP_INIT_CLEANUP,
196 };
197