FFmpeg: libavcodec/dxtory.c Source File

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libavcodec

dxtory.c

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1 /*

2 * Dxtory decoder

3 *

5 *

6 * This file is part of FFmpeg.

7 *

8 * FFmpeg is free software; you can redistribute it and/or

9 * modify it under the terms of the GNU Lesser General Public

10 * License as published by the Free Software Foundation; either

11 * version 2.1 of the License, or (at your option) any later version.

12 *

13 * FFmpeg is distributed in the hope that it will be useful,

14 * but WITHOUT ANY WARRANTY; without even the implied warranty of

15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

16 * Lesser General Public License for more details.

17 *

18 * You should have received a copy of the GNU Lesser General Public

19 * License along with FFmpeg; if not, write to the Free Software

20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

21 */

23 #define BITSTREAM_READER_LE

24 #include "avcodec.h"

25 #include "bytestream.h"

26 #include "get_bits.h"

27 #include "internal.h"

28 #include "unary.h"

29 #include "libavutil/common.h"

30 #include "libavutil/intreadwrite.h"

32 static int dxtory_decode_v1(AVCodecContext *avctx, AVFrame *pic,

33 const uint8_t *src, int src_size)

34 {

35 int h, w;

36 uint8_t *Y1, *Y2, *U, *V;

37 int ret;

39 if (src_size < avctx->width * avctx->height * 3 / 2) {

40 av_log(avctx, AV_LOG_ERROR, "packet too small\n");

41 return AVERROR_INVALIDDATA;

42 }

44 avctx->pix_fmt = AV_PIX_FMT_YUV420P;

45 if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

46 return ret;

48 Y1 = pic->data[0];

49 Y2 = pic->data[0] + pic->linesize[0];

50 U = pic->data[1];

51 V = pic->data[2];

52 for (h = 0; h < avctx->height; h += 2) {

53 for (w = 0; w < avctx->width; w += 2) {

54 AV_COPY16(Y1 + w, src);

55 AV_COPY16(Y2 + w, src + 2);

56 U[w >> 1] = src[4] + 0x80;

57 V[w >> 1] = src[5] + 0x80;

58 src += 6;

59 }

60 Y1 += pic->linesize[0] << 1;

61 Y2 += pic->linesize[0] << 1;

62 U += pic->linesize[1];

63 V += pic->linesize[2];

64 }

66 return 0;

67 }

69 static const uint8_t def_lru[8] = { 0x00, 0x20, 0x40, 0x60, 0x80, 0xA0, 0xC0, 0xFF };

71 static inline uint8_t decode_sym(GetBitContext *gb, uint8_t lru[8])

72 {

73 uint8_t c, val;

75 c = get_unary(gb, 0, 8);

76 if (!c) {

77 val = get_bits(gb, 8);

78 memmove(lru + 1, lru, sizeof(*lru) * (8 - 1));

79 } else {

80 val = lru[c - 1];

81 memmove(lru + 1, lru, sizeof(*lru) * (c - 1));

82 }

83 lru[0] = val;

85 return val;

86 }

88 static int dx2_decode_slice(GetBitContext *gb, int width, int height,

89 uint8_t *Y, uint8_t *U, uint8_t *V,

90 int ystride, int ustride, int vstride)

91 {

92 int x, y, i;

93 uint8_t lru[3][8];

95 for (i = 0; i < 3; i++)

96 memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));

98 for (y = 0; y < height; y+=2) {

99 for (x = 0; x < width; x += 2) {

100 Y[x + 0 + 0 * ystride] = decode_sym(gb, lru[0]);

101 Y[x + 1 + 0 * ystride] = decode_sym(gb, lru[0]);

102 Y[x + 0 + 1 * ystride] = decode_sym(gb, lru[0]);

103 Y[x + 1 + 1 * ystride] = decode_sym(gb, lru[0]);

104 U[x >> 1] = decode_sym(gb, lru[1]) ^ 0x80;

105 V[x >> 1] = decode_sym(gb, lru[2]) ^ 0x80;

106 }

107

108 Y += ystride << 1;

109 U += ustride;

110 V += vstride;

111 }

112

113 return 0;

114 }

115

116 static int dxtory_decode_v2(AVCodecContext *avctx, AVFrame *pic,

117 const uint8_t *src, int src_size)

118 {

119 GetByteContext gb;

120 GetBitContext gb2;

121 int nslices, slice, slice_height;

122 uint32_t off, slice_size;

123 uint8_t *Y, *U, *V;

124 int ret;

125

126 bytestream2_init(&gb, src, src_size);

127 nslices = bytestream2_get_le16(&gb);

128 off = FFALIGN(nslices * 4 + 2, 16);

129 if (src_size < off) {

130 av_log(avctx, AV_LOG_ERROR, "no slice data\n");

131 return AVERROR_INVALIDDATA;

132 }

133

134 if (!nslices || avctx->height % nslices) {

135 avpriv_request_sample(avctx, "%d slices for %dx%d", nslices,

136 avctx->width, avctx->height);

137 return AVERROR(ENOSYS);

138 }

139

140 slice_height = avctx->height / nslices;

141 if ((avctx->width & 1) || (slice_height & 1)) {

142 avpriv_request_sample(avctx, "slice dimensions %dx%d",

143 avctx->width, slice_height);

144 }

145

146 avctx->pix_fmt = AV_PIX_FMT_YUV420P;

147 if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)

148 return ret;

149

150 Y = pic->data[0];

151 U = pic->data[1];

152 V = pic->data[2];

153

154 for (slice = 0; slice < nslices; slice++) {

155 slice_size = bytestream2_get_le32(&gb);

156 if (slice_size > src_size - off) {

157 av_log(avctx, AV_LOG_ERROR,

158 "invalid slice size %d (only %d bytes left)\n",

159 slice_size, src_size - off);

160 return AVERROR_INVALIDDATA;

161 }

162 if (slice_size <= 16) {

163 av_log(avctx, AV_LOG_ERROR, "invalid slice size %d\n", slice_size);

164 return AVERROR_INVALIDDATA;

165 }

166

167 if (AV_RL32(src + off) != slice_size - 16) {

168 av_log(avctx, AV_LOG_ERROR,

169 "Slice sizes mismatch: got %d instead of %d\n",

170 AV_RL32(src + off), slice_size - 16);

171 }

172 init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);

173 dx2_decode_slice(&gb2, avctx->width, slice_height, Y, U, V,

174 pic->linesize[0], pic->linesize[1], pic->linesize[2]);

175

176 Y += pic->linesize[0] * slice_height;

177 U += pic->linesize[1] * (slice_height >> 1);

178 V += pic->linesize[2] * (slice_height >> 1);

179 off += slice_size;

180 }

181

182 return 0;

183 }

184

185 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

186 AVPacket *avpkt)

187 {

188 AVFrame *pic = data;

189 const uint8_t *src = avpkt->data;

190 int ret;

191

192 if (avpkt->size < 16) {

193 av_log(avctx, AV_LOG_ERROR, "packet too small\n");

194 return AVERROR_INVALIDDATA;

195 }

196

197 switch (AV_RB32(src)) {

198 case 0x02000001:

199 ret = dxtory_decode_v1(avctx, pic, src + 16, avpkt->size - 16);

200 break;

201 case 0x02000009:

202 ret = dxtory_decode_v2(avctx, pic, src + 16, avpkt->size - 16);

203 break;

204 default:

205 avpriv_request_sample(avctx, "Frame header %X", AV_RB32(src));

206 return AVERROR_PATCHWELCOME;

207 }

208

209 if (ret)

210 return ret;

211

212 pic->pict_type = AV_PICTURE_TYPE_I;

213 pic->key_frame = 1;

214 *got_frame = 1;

215

216 return avpkt->size;

217 }

218

219 AVCodec ff_dxtory_decoder = {

220 .name = "dxtory",

221 .long_name = NULL_IF_CONFIG_SMALL("Dxtory"),

222 .type = AVMEDIA_TYPE_VIDEO,

223 .id = AV_CODEC_ID_DXTORY,

224 .decode = decode_frame,

225 .capabilities = CODEC_CAP_DR1,

226 };

Generated on Sat Jan 25 2014 19:51:46 for FFmpeg by doxygen 1.8.2