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
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, 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
216static av_cold int truemotion2rt_decode_init(AVCodecContext *avctx)
217{
218    avctx->pix_fmt = AV_PIX_FMT_YUV410P;
219    return 0;
220}
221
222const 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