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 
29 #define BITSTREAM_READER_LE
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "get_bits.h"
33 #include "internal.h"
34 
35 typedef struct TrueMotion2RTContext {
36     GetBitContext gb;
37     int delta_size;
38     int hscale;
39 } TrueMotion2RTContext;
40 
41 static const int16_t delta_tab2[] = {
42     5, -7, 36, -36,
43 };
44 
45 static const int16_t delta_tab3[] = {
46     2, -3, 8, -8, 18, -18, 36, -36,
47 };
48 
49 static const int16_t delta_tab4[] = {
50     1, -1, 2, -3, 8, -8, 18, -18, 36, -36, 54, -54, 96, -96, 144, -144,
51 };
52 
53 static 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. */
truemotion2rt_decode_header(AVCodecContext *avctx, const AVPacket *avpkt)59 static 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 
truemotion2rt_decode_frame(AVCodecContext *avctx, AVFrame *p, int *got_frame, AVPacket *avpkt)105 static int truemotion2rt_decode_frame(AVCodecContext *avctx, AVFrame *p,
106                                       int *got_frame, AVPacket *avpkt)
107 {
108     TrueMotion2RTContext *s = avctx->priv_data;
109     GetBitContext *gb = &s->gb;
110     uint8_t *dst;
111     int x, y, delta_mode;
112     int ret;
113 
114     ret = truemotion2rt_decode_header(avctx, avpkt);
115     if (ret < 0)
116         return ret;
117 
118     if ((avctx->width + s->hscale - 1)/ s->hscale * avctx->height * s->delta_size > avpkt->size * 8LL * 4)
119         return AVERROR_INVALIDDATA;
120 
121     ret = init_get_bits8(gb, avpkt->data + ret, avpkt->size - ret);
122     if (ret < 0)
123         return ret;
124 
125     ret = ff_get_buffer(avctx, p, 0);
126     if (ret < 0)
127         return ret;
128 
129     skip_bits(gb, 32);
130     delta_mode = s->delta_size - 2;
131     dst = p->data[0];
132     for (y = 0; y < avctx->height; y++) {
133         int diff = 0;
134         for (x = 0; x < avctx->width; x += s->hscale) {
135             diff  += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
136             dst[x] = av_clip_uint8((y ? dst[x - p->linesize[0]] : 0) + diff);
137         }
138         dst += p->linesize[0];
139     }
140 
141     if (s->hscale > 1) {
142         dst = p->data[0];
143         for (y = 0; y < avctx->height; y++) {
144             for (x = 1; x < avctx->width; x += s->hscale)
145                 dst[x] = dst[x - 1];
146             dst += p->linesize[0];
147         }
148     }
149 
150     dst = p->data[0];
151     for (y = 0; y < avctx->height; y++) {
152         for (x = 0; x < avctx->width; x++)
153             dst[x] = av_clip_uint8(dst[x] + (dst[x] - 128) / 3);
154         dst += p->linesize[0];
155     }
156 
157     dst = p->data[1];
158     for (y = 0; y < avctx->height >> 2; y++) {
159         int diff = 0;
160         for (x = 0; x < avctx->width >> 2; x += s->hscale) {
161             diff  += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
162             dst[x] = av_clip_uint8((y ? dst[x - p->linesize[1]] : 128) + diff);
163         }
164         dst += p->linesize[1];
165     }
166 
167     if (s->hscale > 1) {
168         dst = p->data[1];
169         for (y = 0; y < avctx->height >> 2; y++) {
170             for (x = 1; x < avctx->width >> 2; x += s->hscale)
171                 dst[x] = dst[x - 1];
172             dst += p->linesize[1];
173         }
174     }
175 
176     dst = p->data[1];
177     for (y = 0; y < avctx->height >> 2; y++) {
178         for (x = 0; x < avctx->width >> 2; x++)
179             dst[x] += (dst[x] - 128) / 8;
180         dst += p->linesize[1];
181     }
182 
183     dst = p->data[2];
184     for (y = 0; y < avctx->height >> 2; y++) {
185         int diff = 0;
186         for (x = 0; x < avctx->width >> 2; x += s->hscale) {
187             diff  += delta_tabs[delta_mode][get_bits(gb, s->delta_size)];
188             dst[x] = av_clip_uint8((y ? dst[x - p->linesize[2]] : 128) + diff);
189         }
190         dst += p->linesize[2];
191     }
192 
193     if (s->hscale > 1) {
194         dst = p->data[2];
195         for (y = 0; y < avctx->height >> 2; y++) {
196             for (x = 1; x < avctx->width >> 2; x += s->hscale)
197                 dst[x] = dst[x - 1];
198             dst += p->linesize[2];
199         }
200     }
201 
202     dst = p->data[2];
203     for (y = 0; y < avctx->height >> 2; y++) {
204         for (x = 0; x < avctx->width >> 2; x++)
205             dst[x] += (dst[x] - 128) / 8;
206         dst += p->linesize[2];
207     }
208 
209     p->pict_type = AV_PICTURE_TYPE_I;
210     p->key_frame = 1;
211     *got_frame = 1;
212 
213     return avpkt->size;
214 }
215 
truemotion2rt_decode_init(AVCodecContext *avctx)216 static av_cold int truemotion2rt_decode_init(AVCodecContext *avctx)
217 {
218     avctx->pix_fmt = AV_PIX_FMT_YUV410P;
219     return 0;
220 }
221 
222 const FFCodec ff_truemotion2rt_decoder = {
223     .p.name         = "truemotion2rt",
224     .p.long_name    = NULL_IF_CONFIG_SMALL("Duck TrueMotion 2.0 Real Time"),
225     .p.type         = AVMEDIA_TYPE_VIDEO,
226     .p.id           = AV_CODEC_ID_TRUEMOTION2RT,
227     .priv_data_size = sizeof(TrueMotion2RTContext),
228     .init           = truemotion2rt_decode_init,
229     FF_CODEC_DECODE_CB(truemotion2rt_decode_frame),
230     .p.capabilities = AV_CODEC_CAP_DR1,
231     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
232 };
233