FFmpeg: libavcodec/motionpixels.c Source File

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libavcodec

motionpixels.c

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1 /*

2 * Motion Pixels Video Decoder

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 */

22 #include "avcodec.h"

23 #include "get_bits.h"

24 #include "bswapdsp.h"

25 #include "internal.h"

27 #define MAX_HUFF_CODES 16

29 #include "motionpixels_tablegen.h"

31 typedef struct HuffCode {

32 int code;

33 uint8_t size;

34 uint8_t delta;

35 } HuffCode;

37 typedef struct MotionPixelsContext {

38 AVCodecContext *avctx;

39 AVFrame *frame;

40 BswapDSPContext bdsp;

41 uint8_t *changes_map;

42 int offset_bits_len;

43 int codes_count, current_codes_count;

44 int max_codes_bits;

45 HuffCode codes[MAX_HUFF_CODES];

46 VLC vlc;

47 YuvPixel *vpt, *hpt;

48 uint8_t gradient_scale[3];

49 uint8_t *bswapbuf;

50 int bswapbuf_size;

51 } MotionPixelsContext;

53 static av_cold int mp_decode_end(AVCodecContext *avctx)

54 {

55 MotionPixelsContext *mp = avctx->priv_data;

57 av_freep(&mp->changes_map);

58 av_freep(&mp->vpt);

59 av_freep(&mp->hpt);

60 av_freep(&mp->bswapbuf);

61 av_frame_free(&mp->frame);

63 return 0;

64 }

66 static av_cold int mp_decode_init(AVCodecContext *avctx)

67 {

68 MotionPixelsContext *mp = avctx->priv_data;

69 int w4 = (avctx->width + 3) & ~3;

70 int h4 = (avctx->height + 3) & ~3;

72 if(avctx->extradata_size < 2){

73 av_log(avctx, AV_LOG_ERROR, "extradata too small\n");

74 return AVERROR_INVALIDDATA;

75 }

77 motionpixels_tableinit();

78 mp->avctx = avctx;

79 ff_bswapdsp_init(&mp->bdsp);

80 mp->changes_map = av_mallocz_array(avctx->width, h4);

81 mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;

82 mp->vpt = av_mallocz_array(avctx->height, sizeof(YuvPixel));

83 mp->hpt = av_mallocz_array(h4 / 4, w4 / 4 * sizeof(YuvPixel));

84 if (!mp->changes_map || !mp->vpt || !mp->hpt) {

85 av_freep(&mp->changes_map);

86 av_freep(&mp->vpt);

87 av_freep(&mp->hpt);

88 return AVERROR(ENOMEM);

89 }

90 avctx->pix_fmt = AV_PIX_FMT_RGB555;

92 mp->frame = av_frame_alloc();

93 if (!mp->frame) {

94 mp_decode_end(avctx);

95 return AVERROR(ENOMEM);

96 }

98 return 0;

99 }

100

101 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)

102 {

103 uint16_t *pixels;

104 int offset, w, h, color = 0, x, y, i;

105

106 while (count--) {

107 offset = get_bits_long(gb, mp->offset_bits_len);

108 w = get_bits(gb, bits_len) + 1;

109 h = get_bits(gb, bits_len) + 1;

110 if (read_color)

111 color = get_bits(gb, 15);

112 x = offset % mp->avctx->width;

113 y = offset / mp->avctx->width;

114 if (y >= mp->avctx->height)

115 continue;

116 w = FFMIN(w, mp->avctx->width - x);

117 h = FFMIN(h, mp->avctx->height - y);

118 pixels = (uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];

119 while (h--) {

120 mp->changes_map[offset] = w;

121 if (read_color)

122 for (i = 0; i < w; ++i)

123 pixels[i] = color;

124 offset += mp->avctx->width;

125 pixels += mp->frame->linesize[0] / 2;

126 }

127 }

128 }

129

130 static int mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)

131 {

132 while (get_bits1(gb)) {

133 ++size;

134 if (size > mp->max_codes_bits) {

135 av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);

136 return AVERROR_INVALIDDATA;

137 }

138 code <<= 1;

139 if (mp_get_code(mp, gb, size, code + 1) < 0)

140 return AVERROR_INVALIDDATA;

141 }

142 if (mp->current_codes_count >= MAX_HUFF_CODES) {

143 av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");

144 return AVERROR_INVALIDDATA;

145 }

146

147 mp->codes[mp->current_codes_count ].code = code;

148 mp->codes[mp->current_codes_count++].size = size;

149 return 0;

150 }

151

152 static int mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)

153 {

154 if (mp->codes_count == 1) {

155 mp->codes[0].delta = get_bits(gb, 4);

156 } else {

157 int i;

158 int ret;

159

160 mp->max_codes_bits = get_bits(gb, 4);

161 for (i = 0; i < mp->codes_count; ++i)

162 mp->codes[i].delta = get_bits(gb, 4);

163 mp->current_codes_count = 0;

164 if ((ret = mp_get_code(mp, gb, 0, 0)) < 0)

165 return ret;

166 if (mp->current_codes_count < mp->codes_count) {

167 av_log(mp->avctx, AV_LOG_ERROR, "too few codes\n");

168 return AVERROR_INVALIDDATA;

169 }

170 }

171 return 0;

172 }

173

174 static int mp_gradient(MotionPixelsContext *mp, int component, int v)

175 {

176 int delta;

177

178 delta = (v - 7) * mp->gradient_scale[component];

179 mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;

180 return delta;

181 }

182

183 static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)

184 {

185 int color;

186

187 color = *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];

188 return mp_rgb_yuv_table[color];

189 }

190

191 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)

192 {

193 int color;

194

195 color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);

196 *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2] = color;

197 }

198

199 static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)

200 {

201 int i;

202

203 i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);

204 return mp->codes[i].delta;

205 }

206

207 static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)

208 {

209 YuvPixel p;

210 const int y0 = y * mp->avctx->width;

211 int w, i, x = 0;

212

213 p = mp->vpt[y];

214 if (mp->changes_map[y0 + x] == 0) {

215 memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));

216 ++x;

217 }

218 while (x < mp->avctx->width) {

219 w = mp->changes_map[y0 + x];

220 if (w != 0) {

221 if ((y & 3) == 0) {

222 if (mp->changes_map[y0 + x + mp->avctx->width] < w ||

223 mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||

224 mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {

225 for (i = (x + 3) & ~3; i < x + w; i += 4) {

226 mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);

227 }

228 }

229 }

230 x += w;

231 memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));

232 p = mp_get_yuv_from_rgb(mp, x - 1, y);

233 } else {

234 p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));

235 p.y = av_clip_uintp2(p.y, 5);

236 if ((x & 3) == 0) {

237 if ((y & 3) == 0) {

238 p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));

239 p.v = av_clip_intp2(p.v, 5);

240 p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));

241 p.u = av_clip_intp2(p.u, 5);

242 mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;

243 } else {

244 p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;

245 p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;

246 }

247 }

248 mp_set_rgb_from_yuv(mp, x, y, &p);

249 ++x;

250 }

251 }

252 }

253

254 static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)

255 {

256 YuvPixel p;

257 int y, y0;

258

259 av_assert1(mp->changes_map[0]);

260

261 for (y = 0; y < mp->avctx->height; ++y) {

262 if (mp->changes_map[y * mp->avctx->width] != 0) {

263 memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));

264 p = mp_get_yuv_from_rgb(mp, 0, y);

265 } else {

266 p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));

267 p.y = av_clip_uintp2(p.y, 5);

268 if ((y & 3) == 0) {

269 p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));

270 p.v = av_clip_intp2(p.v, 5);

271 p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));

272 p.u = av_clip_intp2(p.u, 5);

273 }

274 mp->vpt[y] = p;

275 mp_set_rgb_from_yuv(mp, 0, y, &p);

276 }

277 }

278 for (y0 = 0; y0 < 2; ++y0)

279 for (y = y0; y < mp->avctx->height; y += 2)

280 mp_decode_line(mp, gb, y);

281 }

282

283 static int mp_decode_frame(AVCodecContext *avctx,

284 void *data, int *got_frame,

285 AVPacket *avpkt)

286 {

287 const uint8_t *buf = avpkt->data;

288 int buf_size = avpkt->size;

289 MotionPixelsContext *mp = avctx->priv_data;

290 GetBitContext gb;

291 int i, count1, count2, sz, ret;

292

293 if ((ret = ff_reget_buffer(avctx, mp->frame)) < 0)

294 return ret;

295

296 /* le32 bitstream msb first */

297 av_fast_padded_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size);

298 if (!mp->bswapbuf)

299 return AVERROR(ENOMEM);

300 mp->bdsp.bswap_buf((uint32_t *) mp->bswapbuf, (const uint32_t *) buf,

301 buf_size / 4);

302 if (buf_size & 3)

303 memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);

304 init_get_bits(&gb, mp->bswapbuf, buf_size * 8);

305

306 memset(mp->changes_map, 0, avctx->width * avctx->height);

307 for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {

308 count1 = get_bits(&gb, 12);

309 count2 = get_bits(&gb, 12);

310 mp_read_changes_map(mp, &gb, count1, 8, i);

311 mp_read_changes_map(mp, &gb, count2, 4, i);

312 }

313

314 mp->codes_count = get_bits(&gb, 4);

315 if (mp->codes_count == 0)

316 goto end;

317

318 if (mp->changes_map[0] == 0) {

319 *(uint16_t *)mp->frame->data[0] = get_bits(&gb, 15);

320 mp->changes_map[0] = 1;

321 }

322 if (mp_read_codes_table(mp, &gb) < 0)

323 goto end;

324

325 sz = get_bits(&gb, 18);

326 if (avctx->extradata[0] != 5)

327 sz += get_bits(&gb, 18);

328 if (sz == 0)

329 goto end;

330

331 if (mp->max_codes_bits <= 0)

332 goto end;

333 if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))

334 goto end;

335 mp_decode_frame_helper(mp, &gb);

336 ff_free_vlc(&mp->vlc);

337

338 end:

339 if ((ret = av_frame_ref(data, mp->frame)) < 0)

340 return ret;

341 *got_frame = 1;

342 return buf_size;

343 }

344

345 AVCodec ff_motionpixels_decoder = {

346 .name = "motionpixels",

347 .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),

348 .type = AVMEDIA_TYPE_VIDEO,

349 .id = AV_CODEC_ID_MOTIONPIXELS,

350 .priv_data_size = sizeof(MotionPixelsContext),

351 .init = mp_decode_init,

352 .close = mp_decode_end,

353 .decode = mp_decode_frame,

354 .capabilities = CODEC_CAP_DR1,

355 };

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