1 /*
2 * Copyright 2015 - 2017 Rockchip Electronics Co. LTD
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "mpp_mem.h"
18 #include "mpp_debug.h"
19
20 #include "mpp_bitwrite.h"
21
mpp_writer_status(MppWriteCtx * ctx)22 MPP_RET mpp_writer_status(MppWriteCtx *ctx)
23 {
24 if (ctx->byte_cnt > ctx->size) {
25 ctx->overflow = 1;
26 return MPP_NOK;
27 }
28
29 return MPP_OK;
30 }
31
mpp_writer_reset(MppWriteCtx * ctx)32 MPP_RET mpp_writer_reset(MppWriteCtx *ctx)
33 {
34 ctx->stream = ctx->buffer;
35 ctx->byte_cnt = 0;
36 ctx->byte_buffer = 0;
37 ctx->buffered_bits = 0;
38 ctx->zero_bytes = 0;
39 ctx->overflow = 0;
40 ctx->emul_cnt = 0;
41
42 return MPP_OK;
43 }
44
mpp_writer_init(MppWriteCtx * ctx,void * p,RK_S32 size)45 MPP_RET mpp_writer_init(MppWriteCtx *ctx, void *p, RK_S32 size)
46 {
47 MPP_RET ret;
48
49 ctx->buffer = p;
50 ctx->stream = p;
51 ctx->size = size;
52 ctx->byte_cnt = 0;
53 ctx->overflow = 0;
54 ctx->byte_buffer = 0;
55 ctx->buffered_bits = 0;
56 ctx->zero_bytes = 0;
57 ctx->emul_cnt = 0;
58
59 ret = mpp_writer_status(ctx);
60 if (ret)
61 mpp_err_f("failed to init with overflow config\n");
62
63 return ret;
64 }
65
mpp_writer_put_raw_bits(MppWriteCtx * ctx,RK_S32 val,RK_S32 len)66 void mpp_writer_put_raw_bits(MppWriteCtx *ctx, RK_S32 val, RK_S32 len)
67 {
68 RK_S32 bits;
69 RK_U32 byte_buffer = ctx->byte_buffer;
70 RK_U8*stream = ctx->stream;
71
72 if (mpp_writer_status(ctx))
73 return;
74
75 mpp_assert(val < (1 << len));
76 mpp_assert(len < 25);
77
78 bits = len + ctx->buffered_bits;
79 val <<= (32 - bits);
80 byte_buffer = byte_buffer | val;
81
82 while (bits > 7) {
83 *stream = (RK_U8)(byte_buffer >> 24);
84
85 bits -= 8;
86 byte_buffer <<= 8;
87 stream++;
88 ctx->byte_cnt++;
89 }
90
91 ctx->byte_buffer = byte_buffer;
92 ctx->buffered_bits = (RK_U8)bits;
93 ctx->stream = stream;
94
95 return;
96 }
97
mpp_writer_flush(MppWriteCtx * ctx)98 void mpp_writer_flush(MppWriteCtx *ctx)
99 {
100 RK_U32 byte_buffer = ctx->byte_buffer;
101 RK_U8*stream = ctx->stream;
102
103 if (mpp_writer_status(ctx))
104 return;
105
106 if (ctx->buffered_bits)
107 *stream = (RK_U8)(byte_buffer >> 24);
108
109 return;
110 }
111
mpp_writer_put_bits(MppWriteCtx * ctx,RK_S32 val,RK_S32 len)112 void mpp_writer_put_bits(MppWriteCtx * ctx, RK_S32 val, RK_S32 len)
113 {
114 RK_S32 bits;
115 RK_U8 *stream = ctx->stream;
116 RK_U32 byte_buffer = ctx->byte_buffer;
117
118 if (val) {
119 mpp_assert(val < (1 << len));
120 mpp_assert(len < 25);
121 }
122 bits = len + ctx->buffered_bits;
123
124 byte_buffer = byte_buffer | ((RK_U32) val << (32 - bits));
125
126 while (bits > 7) {
127 RK_S32 zeroBytes = ctx->zero_bytes;
128 RK_S32 byteCnt = ctx->byte_cnt;
129
130 if (mpp_writer_status(ctx))
131 return;
132
133 *stream = (RK_U8) (byte_buffer >> 24);
134
135 byteCnt++;
136 if ((zeroBytes == 2) && (*stream < 4)) {
137 *stream++ = 3;
138 *stream = (RK_U8) (byte_buffer >> 24);
139 byteCnt++;
140 zeroBytes = 0;
141 ctx->emul_cnt++;
142 }
143
144 if (*stream == 0)
145 zeroBytes++;
146 else
147 zeroBytes = 0;
148
149 bits -= 8;
150 byte_buffer <<= 8;
151 stream++;
152 ctx->zero_bytes = zeroBytes;
153 ctx->byte_cnt = byteCnt;
154 ctx->stream = stream;
155 }
156
157 ctx->buffered_bits = (RK_U8) bits;
158 ctx->byte_buffer = byte_buffer;
159 }
160
mpp_writer_align_zero(MppWriteCtx * ctx)161 void mpp_writer_align_zero(MppWriteCtx *ctx)
162 {
163 if (ctx->buffered_bits)
164 mpp_writer_put_raw_bits(ctx, 0, 8 - ctx->buffered_bits);
165 }
166
mpp_writer_align_one(MppWriteCtx * ctx)167 void mpp_writer_align_one(MppWriteCtx *ctx)
168 {
169 if (ctx->buffered_bits) {
170 RK_S32 len = 8 - ctx->buffered_bits;
171
172 mpp_writer_put_raw_bits(ctx, (1 << len) - 1, len);
173 }
174 }
175
mpp_writer_trailing(MppWriteCtx * ctx)176 void mpp_writer_trailing(MppWriteCtx *ctx)
177 {
178 mpp_writer_put_bits(ctx, 1, 1);
179 if (ctx->buffered_bits)
180 mpp_writer_put_bits(ctx, 0, 8 - ctx->buffered_bits);
181 }
182
mpp_writer_put_ue(MppWriteCtx * ctx,RK_U32 val)183 void mpp_writer_put_ue(MppWriteCtx *ctx, RK_U32 val)
184 {
185 RK_U32 num_bits = 0;
186
187 val++;
188 while (val >> ++num_bits);
189
190 if (num_bits > 12) {
191 RK_U32 tmp;
192
193 tmp = num_bits - 1;
194
195 if (tmp > 24) {
196 tmp -= 24;
197 mpp_writer_put_bits(ctx, 0, 24);
198 }
199
200 mpp_writer_put_bits(ctx, 0, tmp);
201
202 if (num_bits > 24) {
203 num_bits -= 24;
204 mpp_writer_put_bits(ctx, val >> num_bits, 24);
205 val = val >> num_bits;
206 }
207
208 mpp_writer_put_bits(ctx, val, num_bits);
209 } else {
210 mpp_writer_put_bits(ctx, val, 2 * num_bits - 1);
211 }
212 }
213
mpp_writer_put_se(MppWriteCtx * ctx,RK_S32 val)214 void mpp_writer_put_se(MppWriteCtx *ctx, RK_S32 val)
215 {
216 RK_U32 tmp;
217
218 if (val > 0)
219 tmp = (RK_U32)(2 * val - 1);
220 else
221 tmp = (RK_U32)(-2 * val);
222
223 mpp_writer_put_ue(ctx, tmp);
224 }
225
mpp_writer_bytes(MppWriteCtx * ctx)226 RK_S32 mpp_writer_bytes(MppWriteCtx *ctx)
227 {
228 return ctx->byte_cnt + (ctx->buffered_bits > 0);
229 }
230
mpp_writer_bits(MppWriteCtx * ctx)231 RK_S32 mpp_writer_bits(MppWriteCtx *ctx)
232 {
233 return ctx->byte_cnt * 8 + ctx->buffered_bits;
234 }
235
mpp_exp_golomb_signed(RK_S32 val)236 RK_S32 mpp_exp_golomb_signed(RK_S32 val)
237 {
238 RK_S32 tmp = 0;
239
240 if (val > 0)
241 val = 2 * val;
242 else
243 val = -2 * val + 1;
244
245 while (val >> ++tmp)
246 ;
247
248 return tmp * 2 - 1;
249 }
250