| 165 | } |
| 166 | |
| 167 | static double modify_qscale(MPVMainEncContext *const m, const RateControlEntry *rce, |
| 168 | double q, int frame_num) |
| 169 | { |
| 170 | MPVEncContext *const s = &m->s; |
| 171 | RateControlContext *const rcc = &m->rc_context; |
| 172 | const double buffer_size = s->c.avctx->rc_buffer_size; |
| 173 | const double fps = get_fps(s->c.avctx); |
| 174 | const double min_rate = s->c.avctx->rc_min_rate / fps; |
| 175 | const double max_rate = s->c.avctx->rc_max_rate / fps; |
| 176 | const int pict_type = rce->new_pict_type; |
| 177 | int qmin, qmax; |
| 178 | |
| 179 | get_qminmax(&qmin, &qmax, m, pict_type); |
| 180 | |
| 181 | /* modulation */ |
| 182 | if (rcc->qmod_freq && |
| 183 | frame_num % rcc->qmod_freq == 0 && |
| 184 | pict_type == AV_PICTURE_TYPE_P) |
| 185 | q *= rcc->qmod_amp; |
| 186 | |
| 187 | /* buffer overflow/underflow protection */ |
| 188 | if (buffer_size) { |
| 189 | double expected_size = rcc->buffer_index; |
| 190 | double q_limit; |
| 191 | |
| 192 | if (min_rate) { |
| 193 | double d = 2 * (buffer_size - expected_size) / buffer_size; |
| 194 | if (d > 1.0) |
| 195 | d = 1.0; |
| 196 | else if (d < 0.0001) |
| 197 | d = 0.0001; |
| 198 | q *= pow(d, 1.0 / rcc->buffer_aggressivity); |
| 199 | |
| 200 | q_limit = bits2qp(rce, |
| 201 | FFMAX((min_rate - buffer_size + rcc->buffer_index) * |
| 202 | s->c.avctx->rc_min_vbv_overflow_use, 1)); |
| 203 | |
| 204 | if (q > q_limit) { |
| 205 | if (s->c.avctx->debug & FF_DEBUG_RC) |
| 206 | av_log(s->c.avctx, AV_LOG_DEBUG, |
| 207 | "limiting QP %f -> %f\n", q, q_limit); |
| 208 | q = q_limit; |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | if (max_rate) { |
| 213 | double d = 2 * expected_size / buffer_size; |
| 214 | if (d > 1.0) |
| 215 | d = 1.0; |
| 216 | else if (d < 0.0001) |
| 217 | d = 0.0001; |
| 218 | q /= pow(d, 1.0 / rcc->buffer_aggressivity); |
| 219 | |
| 220 | q_limit = bits2qp(rce, |
| 221 | FFMAX(rcc->buffer_index * |
| 222 | s->c.avctx->rc_max_available_vbv_use, |
| 223 | 1)); |
| 224 | if (q < q_limit) { |
no test coverage detected