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path: root/libavcodec/truemotion2rt.c (plain)
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1/*
2 * Duck TrueMotion 2.0 Real Time decoder
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 <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24
25#include "libavutil/imgutils.h"
26#include "libavutil/internal.h"
27#include "libavutil/intreadwrite.h"
28#include "libavutil/mem.h"
29
30#define BITSTREAM_READER_LE
31#include "avcodec.h"
32#include "get_bits.h"
33#include "internal.h"
34
35typedef struct TrueMotion2RTContext {
36 GetBitContext gb;
37 int delta_size;
38 int hscale;
39} TrueMotion2RTContext;
40
41static const int16_t delta_tab2[] = {
42 5, -7, 36, -36,
43};
44
45static const int16_t delta_tab3[] = {
46 2, -3, 8, -8, 18, -18, 36, -36,
47};
48
49static const int16_t delta_tab4[] = {
50 1, -1, 2, -3, 8, -8, 18, -18, 36, -36, 54, -54, 96, -96, 144, -144,
51};
52
53static const int16_t *const delta_tabs[] = {
54 delta_tab2, delta_tab3, delta_tab4,
55};
56
57/* Returns the number of bytes consumed from the bytestream, or
58 * AVERROR_INVALIDDATA if there was an error while decoding the header. */
59static int truemotion2rt_decode_header(AVCodecContext *avctx, const AVPacket *avpkt)
60{
61 TrueMotion2RTContext *s = avctx->priv_data;
62 int header_size;
63 uint8_t header_buffer[128] = { 0 }; /* logical maximum header size */
64 const uint8_t *buf = avpkt->data;
65 int size = avpkt->size;
66 int width, height;
67 int ret, i;
68
69 if (size < 1) {
70 av_log(avctx, AV_LOG_ERROR, "input packet too small (%d)\n", size);
71 return AVERROR_INVALIDDATA;
72 }
73
74 header_size = ((buf[0] >> 5) | (buf[0] << 3)) & 0x7f;
75 if (header_size < 10) {
76 av_log(avctx, AV_LOG_ERROR, "invalid header size (%d)\n", header_size);
77 return AVERROR_INVALIDDATA;
78 }
79
80 if (header_size + 1 > size) {
81 av_log(avctx, AV_LOG_ERROR, "input packet too small (%d)\n", size);
82 return AVERROR_INVALIDDATA;
83 }
84
85 /* unscramble the header bytes with a XOR operation */
86 for (i = 1; i < header_size; i++)
87 header_buffer[i - 1] = buf[i] ^ buf[i + 1];
88
89 s->delta_size = header_buffer[1];
90 s->hscale = 1 + !!header_buffer[3];
91 if (s->delta_size < 2 || s->delta_size > 4)
92 return AVERROR_INVALIDDATA;
93
94 height = AV_RL16(header_buffer + 5);
95 width = AV_RL16(header_buffer + 7);
96
97 ret = ff_set_dimensions(avctx, width, height);
98 if (ret < 0)
99 return ret;
100
101 av_log(avctx, AV_LOG_DEBUG, "Header size: %d\n", header_size);
102 return header_size;
103}
104
105static int truemotion2rt_decode_frame(AVCodecContext *avctx, void *data,
106 int *got_frame, AVPacket *avpkt)
107{
108 TrueMotion2RTContext *s = avctx->priv_data;
109 AVFrame * const p = data;
110 GetBitContext *gb = &s->gb;
111 uint8_t *dst;
112 int x, y, delta_mode;
113 int ret;
114
115 ret = truemotion2rt_decode_header(avctx, avpkt);
116 if (ret < 0)
117 return ret;
118
119 ret = init_get_bits8(gb, avpkt->data + ret, avpkt->size - ret);
120 if (ret < 0)
121 return ret;
122
123 ret = ff_get_buffer(avctx, p, 0);
124 if (ret < 0)
125 return ret;
126
127 skip_bits(gb, 32);
128 delta_mode = s->delta_size - 2;
129 dst = p->data[0];
130 for (y = 0; y < avctx->height; y++) {
131 int diff = 0;
132 for (x = 0; x < avctx->width; x += s->hscale) {
133 diff += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
134 dst[x] = av_clip_uint8((y ? dst[x - p->linesize[0]] : 0) + diff);
135 }
136 dst += p->linesize[0];
137 }
138
139 if (s->hscale > 1) {
140 dst = p->data[0];
141 for (y = 0; y < avctx->height; y++) {
142 for (x = 1; x < avctx->width; x += s->hscale)
143 dst[x] = dst[x - 1];
144 dst += p->linesize[0];
145 }
146 }
147
148 dst = p->data[0];
149 for (y = 0; y < avctx->height; y++) {
150 for (x = 0; x < avctx->width; x++)
151 dst[x] = av_clip_uint8(dst[x] + (dst[x] - 128) / 3);
152 dst += p->linesize[0];
153 }
154
155 dst = p->data[1];
156 for (y = 0; y < avctx->height >> 2; y++) {
157 int diff = 0;
158 for (x = 0; x < avctx->width >> 2; x += s->hscale) {
159 diff += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
160 dst[x] = av_clip_uint8((y ? dst[x - p->linesize[1]] : 128) + diff);
161 }
162 dst += p->linesize[1];
163 }
164
165 if (s->hscale > 1) {
166 dst = p->data[1];
167 for (y = 0; y < avctx->height >> 2; y++) {
168 for (x = 1; x < avctx->width >> 2; x += s->hscale)
169 dst[x] = dst[x - 1];
170 dst += p->linesize[1];
171 }
172 }
173
174 dst = p->data[1];
175 for (y = 0; y < avctx->height >> 2; y++) {
176 for (x = 0; x < avctx->width >> 2; x++)
177 dst[x] += (dst[x] - 128) / 8;
178 dst += p->linesize[1];
179 }
180
181 dst = p->data[2];
182 for (y = 0; y < avctx->height >> 2; y++) {
183 int diff = 0;
184 for (x = 0; x < avctx->width >> 2; x += s->hscale) {
185 diff += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
186 dst[x] = av_clip_uint8((y ? dst[x - p->linesize[2]] : 128) + diff);
187 }
188 dst += p->linesize[2];
189 }
190
191 if (s->hscale > 1) {
192 dst = p->data[2];
193 for (y = 0; y < avctx->height >> 2; y++) {
194 for (x = 1; x < avctx->width >> 2; x += s->hscale)
195 dst[x] = dst[x - 1];
196 dst += p->linesize[2];
197 }
198 }
199
200 dst = p->data[2];
201 for (y = 0; y < avctx->height >> 2; y++) {
202 for (x = 0; x < avctx->width >> 2; x++)
203 dst[x] += (dst[x] - 128) / 8;
204 dst += p->linesize[2];
205 }
206
207 p->pict_type = AV_PICTURE_TYPE_I;
208 p->key_frame = 1;
209 *got_frame = 1;
210
211 return avpkt->size;
212}
213
214static av_cold int truemotion2rt_decode_init(AVCodecContext *avctx)
215{
216 avctx->pix_fmt = AV_PIX_FMT_YUV410P;
217 return 0;
218}
219
220AVCodec ff_truemotion2rt_decoder = {
221 .name = "truemotion2rt",
222 .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 2.0 Real Time"),
223 .type = AVMEDIA_TYPE_VIDEO,
224 .id = AV_CODEC_ID_TRUEMOTION2RT,
225 .priv_data_size = sizeof(TrueMotion2RTContext),
226 .init = truemotion2rt_decode_init,
227 .decode = truemotion2rt_decode_frame,
228 .capabilities = AV_CODEC_CAP_DR1,
229 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
230};
231
generated by cgit at 2024-05-17 04:11:16 (GMT)