FFmpeg: libavcodec/roqvideodec.c Source File

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libavcodec

roqvideodec.c

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1 /*

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 */

21 /**

22 * @file

23 * id RoQ Video Decoder by Dr. Tim Ferguson

24 * For more information about the id RoQ format, visit:

25 * http://www.csse.monash.edu.au/~timf/

26 */

28 #include "libavutil/avassert.h"

29 #include "avcodec.h"

30 #include "bytestream.h"

31 #include "internal.h"

32 #include "roqvideo.h"

34 static void roqvideo_decode_frame(RoqContext *ri)

35 {

36 unsigned int chunk_id = 0, chunk_arg = 0;

37 unsigned long chunk_size = 0;

38 int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;

39 int vqid, xpos, ypos, xp, yp, x, y, mx, my;

40 int frame_stats[2][4] = {{0},{0}};

41 roq_qcell *qcell;

42 int64_t chunk_start;

44 while (bytestream2_get_bytes_left(&ri->gb) >= 8) {

45 chunk_id = bytestream2_get_le16(&ri->gb);

46 chunk_size = bytestream2_get_le32(&ri->gb);

47 chunk_arg = bytestream2_get_le16(&ri->gb);

49 if(chunk_id == RoQ_QUAD_VQ)

50 break;

51 if(chunk_id == RoQ_QUAD_CODEBOOK) {

52 if((nv1 = chunk_arg >> 8) == 0)

53 nv1 = 256;

54 if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)

55 nv2 = 256;

56 for(i = 0; i < nv1; i++) {

57 ri->cb2x2[i].y[0] = bytestream2_get_byte(&ri->gb);

58 ri->cb2x2[i].y[1] = bytestream2_get_byte(&ri->gb);

59 ri->cb2x2[i].y[2] = bytestream2_get_byte(&ri->gb);

60 ri->cb2x2[i].y[3] = bytestream2_get_byte(&ri->gb);

61 ri->cb2x2[i].u = bytestream2_get_byte(&ri->gb);

62 ri->cb2x2[i].v = bytestream2_get_byte(&ri->gb);

63 }

64 for(i = 0; i < nv2; i++)

65 for(j = 0; j < 4; j++)

66 ri->cb4x4[i].idx[j] = bytestream2_get_byte(&ri->gb);

67 }

68 }

70 chunk_start = bytestream2_tell(&ri->gb);

71 xpos = ypos = 0;

73 if (chunk_size > bytestream2_get_bytes_left(&ri->gb)) {

74 av_log(ri->avctx, AV_LOG_ERROR, "Chunk does not fit in input buffer\n");

75 chunk_size = bytestream2_get_bytes_left(&ri->gb);

76 }

78 while (bytestream2_tell(&ri->gb) < chunk_start + chunk_size) {

79 for (yp = ypos; yp < ypos + 16; yp += 8)

80 for (xp = xpos; xp < xpos + 16; xp += 8) {

81 if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {

82 av_log(ri->avctx, AV_LOG_ERROR, "Input buffer too small\n");

83 return;

84 }

85 if (vqflg_pos < 0) {

86 vqflg = bytestream2_get_le16(&ri->gb);

87 vqflg_pos = 7;

88 }

89 vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;

90 frame_stats[0][vqid]++;

91 vqflg_pos--;

93 switch(vqid) {

94 case RoQ_ID_MOT:

95 break;

96 case RoQ_ID_FCC: {

97 int byte = bytestream2_get_byte(&ri->gb);

98 mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));

99 my = 8 - (byte & 0xf) - ((signed char) chunk_arg);

100 ff_apply_motion_8x8(ri, xp, yp, mx, my);

101 break;

102 }

103 case RoQ_ID_SLD:

104 qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);

105 ff_apply_vector_4x4(ri, xp, yp, ri->cb2x2 + qcell->idx[0]);

106 ff_apply_vector_4x4(ri, xp + 4, yp, ri->cb2x2 + qcell->idx[1]);

107 ff_apply_vector_4x4(ri, xp, yp + 4, ri->cb2x2 + qcell->idx[2]);

108 ff_apply_vector_4x4(ri, xp + 4, yp + 4, ri->cb2x2 + qcell->idx[3]);

109 break;

110 case RoQ_ID_CCC:

111 for (k = 0; k < 4; k++) {

112 x = xp; y = yp;

113 if(k & 0x01) x += 4;

114 if(k & 0x02) y += 4;

115

116 if (bytestream2_tell(&ri->gb) >= chunk_start + chunk_size) {

117 av_log(ri->avctx, AV_LOG_ERROR, "Input buffer too small\n");

118 return;

119 }

120 if (vqflg_pos < 0) {

121 vqflg = bytestream2_get_le16(&ri->gb);

122 vqflg_pos = 7;

123 }

124 vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;

125 frame_stats[1][vqid]++;

126 vqflg_pos--;

127 switch(vqid) {

128 case RoQ_ID_MOT:

129 break;

130 case RoQ_ID_FCC: {

131 int byte = bytestream2_get_byte(&ri->gb);

132 mx = 8 - (byte >> 4) - ((signed char) (chunk_arg >> 8));

133 my = 8 - (byte & 0xf) - ((signed char) chunk_arg);

134 ff_apply_motion_4x4(ri, x, y, mx, my);

135 break;

136 }

137 case RoQ_ID_SLD:

138 qcell = ri->cb4x4 + bytestream2_get_byte(&ri->gb);

139 ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + qcell->idx[0]);

140 ff_apply_vector_2x2(ri, x + 2, y, ri->cb2x2 + qcell->idx[1]);

141 ff_apply_vector_2x2(ri, x, y + 2, ri->cb2x2 + qcell->idx[2]);

142 ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + qcell->idx[3]);

143 break;

144 case RoQ_ID_CCC:

145 ff_apply_vector_2x2(ri, x, y, ri->cb2x2 + bytestream2_get_byte(&ri->gb));

146 ff_apply_vector_2x2(ri, x + 2, y, ri->cb2x2 + bytestream2_get_byte(&ri->gb));

147 ff_apply_vector_2x2(ri, x, y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));

148 ff_apply_vector_2x2(ri, x + 2, y + 2, ri->cb2x2 + bytestream2_get_byte(&ri->gb));

149 break;

150 }

151 }

152 break;

153 default:

154 av_assert2(0);

155 }

156 }

157

158 xpos += 16;

159 if (xpos >= ri->width) {

160 xpos -= ri->width;

161 ypos += 16;

162 }

163 if(ypos >= ri->height)

164 break;

165 }

166 }

167

168

169 static av_cold int roq_decode_init(AVCodecContext *avctx)

170 {

171 RoqContext *s = avctx->priv_data;

172

173 s->avctx = avctx;

174

175 if (avctx->width % 16 || avctx->height % 16) {

176 av_log(avctx, AV_LOG_ERROR,

177 "Dimensions must be a multiple of 16\n");

178 return AVERROR_PATCHWELCOME;

179 }

180

181 s->width = avctx->width;

182 s->height = avctx->height;

183

184 s->last_frame = av_frame_alloc();

185 s->current_frame = av_frame_alloc();

186 if (!s->current_frame || !s->last_frame) {

187 av_frame_free(&s->current_frame);

188 av_frame_free(&s->last_frame);

189 return AVERROR(ENOMEM);

190 }

191

192 avctx->pix_fmt = AV_PIX_FMT_YUV444P;

193

194 return 0;

195 }

196

197 static int roq_decode_frame(AVCodecContext *avctx,

198 void *data, int *got_frame,

199 AVPacket *avpkt)

200 {

201 const uint8_t *buf = avpkt->data;

202 int buf_size = avpkt->size;

203 RoqContext *s = avctx->priv_data;

204 int copy= !s->current_frame->data[0];

205 int ret;

206

207 if ((ret = ff_reget_buffer(avctx, s->current_frame)) < 0)

208 return ret;

209

210 if(copy)

211 av_picture_copy((AVPicture*)s->current_frame, (AVPicture*)s->last_frame,

212 avctx->pix_fmt, avctx->width, avctx->height);

213

214 bytestream2_init(&s->gb, buf, buf_size);

215 roqvideo_decode_frame(s);

216

217 if ((ret = av_frame_ref(data, s->current_frame)) < 0)

218 return ret;

219 *got_frame = 1;

220

221 /* shuffle frames */

222 FFSWAP(AVFrame *, s->current_frame, s->last_frame);

223

224 return buf_size;

225 }

226

227 static av_cold int roq_decode_end(AVCodecContext *avctx)

228 {

229 RoqContext *s = avctx->priv_data;

230

231 av_frame_free(&s->current_frame);

232 av_frame_free(&s->last_frame);

233

234 return 0;

235 }

236

237 AVCodec ff_roq_decoder = {

238 .name = "roqvideo",

239 .long_name = NULL_IF_CONFIG_SMALL("id RoQ video"),

240 .type = AVMEDIA_TYPE_VIDEO,

241 .id = AV_CODEC_ID_ROQ,

242 .priv_data_size = sizeof(RoqContext),

243 .init = roq_decode_init,

244 .close = roq_decode_end,

245 .decode = roq_decode_frame,

246 .capabilities = CODEC_CAP_DR1,

247 };

Generated on Sat Jan 25 2014 19:51:54 for FFmpeg by doxygen 1.8.2