FFmpeg: libavcodec/cdxl.c Source File

FFmpeg

[フレーム]

libavcodec

cdxl.c

Go to the documentation of this file.

1 /*

2 * CDXL 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 /**

23 * @file

24 * Commodore CDXL video decoder

25 * @author Paul B Mahol

26 */

28 #define UNCHECKED_BITSTREAM_READER 1

30 #include "libavutil/intreadwrite.h"

31 #include "libavutil/imgutils.h"

32 #include "avcodec.h"

33 #include "get_bits.h"

34 #include "internal.h"

36 #define BIT_PLANAR 0x00

37 #define CHUNKY 0x20

38 #define BYTE_PLANAR 0x40

39 #define BIT_LINE 0x80

40 #define BYTE_LINE 0xC0

42 typedef struct {

43 AVCodecContext *avctx;

44 int bpp;

45 int format;

46 int padded_bits;

47 const uint8_t *palette;

48 int palette_size;

49 const uint8_t *video;

50 int video_size;

51 uint8_t *new_video;

52 int new_video_size;

53 } CDXLVideoContext;

55 static av_cold int cdxl_decode_init(AVCodecContext *avctx)

56 {

57 CDXLVideoContext *c = avctx->priv_data;

59 c->new_video_size = 0;

60 c->avctx = avctx;

62 return 0;

63 }

65 static void import_palette(CDXLVideoContext *c, uint32_t *new_palette)

66 {

67 int i;

69 for (i = 0; i < c->palette_size / 2; i++) {

70 unsigned rgb = AV_RB16(&c->palette[i * 2]);

71 unsigned r = ((rgb >> 8) & 0xF) * 0x11;

72 unsigned g = ((rgb >> 4) & 0xF) * 0x11;

73 unsigned b = (rgb & 0xF) * 0x11;

74 AV_WN32(&new_palette[i], (0xFFU << 24) | (r << 16) | (g << 8) | b);

75 }

76 }

78 static void bitplanar2chunky(CDXLVideoContext *c, int linesize, uint8_t *out)

79 {

80 GetBitContext gb;

81 int x, y, plane;

83 init_get_bits(&gb, c->video, c->video_size * 8);

84 for (plane = 0; plane < c->bpp; plane++) {

85 for (y = 0; y < c->avctx->height; y++) {

86 for (x = 0; x < c->avctx->width; x++)

87 out[linesize * y + x] |= get_bits1(&gb) << plane;

88 skip_bits(&gb, c->padded_bits);

89 }

90 }

91 }

93 static void bitline2chunky(CDXLVideoContext *c, int linesize, uint8_t *out)

94 {

95 GetBitContext gb;

96 int x, y, plane;

98 init_get_bits(&gb, c->video, c->video_size * 8);

99 for (y = 0; y < c->avctx->height; y++) {

100 for (plane = 0; plane < c->bpp; plane++) {

101 for (x = 0; x < c->avctx->width; x++)

102 out[linesize * y + x] |= get_bits1(&gb) << plane;

103 skip_bits(&gb, c->padded_bits);

104 }

105 }

106 }

107

108 static void import_format(CDXLVideoContext *c, int linesize, uint8_t *out)

109 {

110 memset(out, 0, linesize * c->avctx->height);

111

112 switch (c->format) {

113 case BIT_PLANAR:

114 bitplanar2chunky(c, linesize, out);

115 break;

116 case BIT_LINE:

117 bitline2chunky(c, linesize, out);

118 break;

119 }

120 }

121

122 static void cdxl_decode_rgb(CDXLVideoContext *c, AVFrame *frame)

123 {

124 uint32_t *new_palette = (uint32_t *)frame->data[1];

125

126 memset(frame->data[1], 0, AVPALETTE_SIZE);

127 import_palette(c, new_palette);

128 import_format(c, frame->linesize[0], frame->data[0]);

129 }

130

131 static void cdxl_decode_ham6(CDXLVideoContext *c, AVFrame *frame)

132 {

133 AVCodecContext *avctx = c->avctx;

134 uint32_t new_palette[16], r, g, b;

135 uint8_t *ptr, *out, index, op;

136 int x, y;

137

138 ptr = c->new_video;

139 out = frame->data[0];

140

141 import_palette(c, new_palette);

142 import_format(c, avctx->width, c->new_video);

143

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

145 r = new_palette[0] & 0xFF0000;

146 g = new_palette[0] & 0xFF00;

147 b = new_palette[0] & 0xFF;

148 for (x = 0; x < avctx->width; x++) {

149 index = *ptr++;

150 op = index >> 4;

151 index &= 15;

152 switch (op) {

153 case 0:

154 r = new_palette[index] & 0xFF0000;

155 g = new_palette[index] & 0xFF00;

156 b = new_palette[index] & 0xFF;

157 break;

158 case 1:

159 b = index * 0x11;

160 break;

161 case 2:

162 r = index * 0x11 << 16;

163 break;

164 case 3:

165 g = index * 0x11 << 8;

166 break;

167 }

168 AV_WL24(out + x * 3, r | g | b);

169 }

170 out += frame->linesize[0];

171 }

172 }

173

174 static void cdxl_decode_ham8(CDXLVideoContext *c, AVFrame *frame)

175 {

176 AVCodecContext *avctx = c->avctx;

177 uint32_t new_palette[64], r, g, b;

178 uint8_t *ptr, *out, index, op;

179 int x, y;

180

181 ptr = c->new_video;

182 out = frame->data[0];

183

184 import_palette(c, new_palette);

185 import_format(c, avctx->width, c->new_video);

186

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

188 r = new_palette[0] & 0xFF0000;

189 g = new_palette[0] & 0xFF00;

190 b = new_palette[0] & 0xFF;

191 for (x = 0; x < avctx->width; x++) {

192 index = *ptr++;

193 op = index >> 6;

194 index &= 63;

195 switch (op) {

196 case 0:

197 r = new_palette[index] & 0xFF0000;

198 g = new_palette[index] & 0xFF00;

199 b = new_palette[index] & 0xFF;

200 break;

201 case 1:

202 b = (index << 2) | (b & 3);

203 break;

204 case 2:

205 r = (index << 18) | (r & (3 << 16));

206 break;

207 case 3:

208 g = (index << 10) | (g & (3 << 8));

209 break;

210 }

211 AV_WL24(out + x * 3, r | g | b);

212 }

213 out += frame->linesize[0];

214 }

215 }

216

217 static int cdxl_decode_frame(AVCodecContext *avctx, void *data,

218 int *got_frame, AVPacket *pkt)

219 {

220 CDXLVideoContext *c = avctx->priv_data;

221 AVFrame * const p = data;

222 int ret, w, h, encoding, aligned_width, buf_size = pkt->size;

223 const uint8_t *buf = pkt->data;

224

225 if (buf_size < 32)

226 return AVERROR_INVALIDDATA;

227 encoding = buf[1] & 7;

228 c->format = buf[1] & 0xE0;

229 w = AV_RB16(&buf[14]);

230 h = AV_RB16(&buf[16]);

231 c->bpp = buf[19];

232 c->palette_size = AV_RB16(&buf[20]);

233 c->palette = buf + 32;

234 c->video = c->palette + c->palette_size;

235 c->video_size = buf_size - c->palette_size - 32;

236

237 if (c->palette_size > 512)

238 return AVERROR_INVALIDDATA;

239 if (buf_size < c->palette_size + 32)

240 return AVERROR_INVALIDDATA;

241 if (c->bpp < 1)

242 return AVERROR_INVALIDDATA;

243 if (c->format != BIT_PLANAR && c->format != BIT_LINE) {

244 avpriv_request_sample(avctx, "Pixel format 0x%0x", c->format);

245 return AVERROR_PATCHWELCOME;

246 }

247

248 if ((ret = ff_set_dimensions(avctx, w, h)) < 0)

249 return ret;

250

251 aligned_width = FFALIGN(c->avctx->width, 16);

252 c->padded_bits = aligned_width - c->avctx->width;

253 if (c->video_size < aligned_width * avctx->height * c->bpp / 8)

254 return AVERROR_INVALIDDATA;

255 if (!encoding && c->palette_size && c->bpp <= 8) {

256 avctx->pix_fmt = AV_PIX_FMT_PAL8;

257 } else if (encoding == 1 && (c->bpp == 6 || c->bpp == 8)) {

258 if (c->palette_size != (1 << (c->bpp - 1)))

259 return AVERROR_INVALIDDATA;

260 avctx->pix_fmt = AV_PIX_FMT_BGR24;

261 } else {

262 avpriv_request_sample(avctx, "Encoding %d and bpp %d",

263 encoding, c->bpp);

264 return AVERROR_PATCHWELCOME;

265 }

266

267 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)

268 return ret;

269 p->pict_type = AV_PICTURE_TYPE_I;

270

271 if (encoding) {

272 av_fast_padded_malloc(&c->new_video, &c->new_video_size,

273 h * w + FF_INPUT_BUFFER_PADDING_SIZE);

274 if (!c->new_video)

275 return AVERROR(ENOMEM);

276 if (c->bpp == 8)

277 cdxl_decode_ham8(c, p);

278 else

279 cdxl_decode_ham6(c, p);

280 } else {

281 cdxl_decode_rgb(c, p);

282 }

283 *got_frame = 1;

284

285 return buf_size;

286 }

287

288 static av_cold int cdxl_decode_end(AVCodecContext *avctx)

289 {

290 CDXLVideoContext *c = avctx->priv_data;

291

292 av_freep(&c->new_video);

293

294 return 0;

295 }

296

297 AVCodec ff_cdxl_decoder = {

298 .name = "cdxl",

299 .long_name = NULL_IF_CONFIG_SMALL("Commodore CDXL video"),

300 .type = AVMEDIA_TYPE_VIDEO,

301 .id = AV_CODEC_ID_CDXL,

302 .priv_data_size = sizeof(CDXLVideoContext),

303 .init = cdxl_decode_init,

304 .close = cdxl_decode_end,

305 .decode = cdxl_decode_frame,

306 .capabilities = CODEC_CAP_DR1,

307 };

Generated on Sun Jul 20 2014 23:05:45 for FFmpeg by doxygen 1.8.2