1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Vidtv serves as a reference DVB driver and helps validate the existing APIs 4 * in the media subsystem. It can also aid developers working on userspace 5 * applications. 6 * 7 * This file contains the code for an AES3 (also known as AES/EBU) encoder. 8 * It is based on EBU Tech 3250 and SMPTE 302M technical documents. 9 * 10 * This encoder currently supports 16bit AES3 subframes using 16bit signed 11 * integers. 12 * 13 * Note: AU stands for Access Unit, and AAU stands for Audio Access Unit 14 * 15 * Copyright (C) 2020 Daniel W. S. Almeida 16 */ 17 18 #define pr_fmt(fmt) KBUILD_MODNAME ":%s, %d: " fmt, __func__, __LINE__ 19 20 #include <linux/bug.h> 21 #include <linux/crc32.h> 22 #include <linux/fixp-arith.h> 23 #include <linux/jiffies.h> 24 #include <linux/kernel.h> 25 #include <linux/math64.h> 26 #include <linux/printk.h> 27 #include <linux/ratelimit.h> 28 #include <linux/slab.h> 29 #include <linux/string.h> 30 #include <linux/types.h> 31 #include <linux/vmalloc.h> 32 33 #include "vidtv_common.h" 34 #include "vidtv_encoder.h" 35 #include "vidtv_s302m.h" 36 37 #define S302M_SAMPLING_RATE_HZ 48000 38 #define PES_PRIVATE_STREAM_1 0xbd /* PES: private_stream_1 */ 39 #define S302M_BLOCK_SZ 192 40 #define S302M_SIN_LUT_NUM_ELEM 1024 41 42 /* these are retrieved empirically from ffmpeg/libavcodec */ 43 #define FF_S302M_DEFAULT_NUM_FRAMES 1115 44 #define FF_S302M_DEFAULT_PTS_INCREMENT 2090 45 #define FF_S302M_DEFAULT_PTS_OFFSET 100000 46 47 /* Used by the tone generator: number of samples for PI */ 48 #define PI 180 49 50 static const u8 reverse[256] = { 51 /* from ffmpeg */ 52 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 53 0x30, 0xB0, 0x70, 0xF0, 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 54 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, 0x04, 0x84, 0x44, 0xC4, 55 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, 56 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 57 0x3C, 0xBC, 0x7C, 0xFC, 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 58 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, 0x0A, 0x8A, 0x4A, 0xCA, 59 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, 60 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 61 0x36, 0xB6, 0x76, 0xF6, 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 62 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, 0x01, 0x81, 0x41, 0xC1, 63 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, 64 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9, 65 0x39, 0xB9, 0x79, 0xF9, 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 66 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, 0x0D, 0x8D, 0x4D, 0xCD, 67 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, 68 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 69 0x33, 0xB3, 0x73, 0xF3, 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 70 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, 0x07, 0x87, 0x47, 0xC7, 71 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, 72 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 73 0x3F, 0xBF, 0x7F, 0xFF, 74 }; 75 76 struct tone_duration { 77 enum musical_notes note; 78 int duration; 79 }; 80 81 #define COMPASS 100 /* beats per minute */ 82 static const struct tone_duration beethoven_fur_elise[] = { 83 { NOTE_SILENT, 512}, 84 { NOTE_E_6, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 85 { NOTE_DS_6, 128}, { NOTE_E_6, 128}, { NOTE_B_5, 128}, 86 { NOTE_D_6, 128}, { NOTE_C_6, 128}, { NOTE_A_3, 128}, 87 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_C_5, 128}, 88 { NOTE_E_5, 128}, { NOTE_A_5, 128}, { NOTE_E_3, 128}, 89 { NOTE_E_4, 128}, { NOTE_GS_4, 128}, { NOTE_E_5, 128}, 90 { NOTE_GS_5, 128}, { NOTE_B_5, 128}, { NOTE_A_3, 128}, 91 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_E_5, 128}, 92 { NOTE_E_6, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 93 { NOTE_DS_6, 128}, { NOTE_E_6, 128}, { NOTE_B_5, 128}, 94 { NOTE_D_6, 128}, { NOTE_C_6, 128}, { NOTE_A_3, 128}, 95 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_C_5, 128}, 96 { NOTE_E_5, 128}, { NOTE_A_5, 128}, { NOTE_E_3, 128}, 97 { NOTE_E_4, 128}, { NOTE_GS_4, 128}, { NOTE_E_5, 128}, 98 { NOTE_C_6, 128}, { NOTE_B_5, 128}, { NOTE_A_3, 128}, 99 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_SILENT, 128}, 100 101 { NOTE_E_6, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 102 { NOTE_DS_6, 128}, { NOTE_E_6, 128}, { NOTE_B_5, 128}, 103 { NOTE_D_6, 128}, { NOTE_C_6, 128}, { NOTE_A_3, 128}, 104 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_C_5, 128}, 105 { NOTE_E_5, 128}, { NOTE_A_5, 128}, { NOTE_E_3, 128}, 106 { NOTE_E_4, 128}, { NOTE_GS_4, 128}, { NOTE_E_5, 128}, 107 { NOTE_GS_5, 128}, { NOTE_B_5, 128}, { NOTE_A_3, 128}, 108 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_E_5, 128}, 109 { NOTE_E_6, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 110 { NOTE_DS_6, 128}, { NOTE_E_6, 128}, { NOTE_B_5, 128}, 111 { NOTE_D_6, 128}, { NOTE_C_6, 128}, { NOTE_A_3, 128}, 112 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_C_5, 128}, 113 { NOTE_E_5, 128}, { NOTE_A_5, 128}, { NOTE_E_3, 128}, 114 { NOTE_E_4, 128}, { NOTE_GS_4, 128}, { NOTE_E_5, 128}, 115 { NOTE_C_6, 128}, { NOTE_B_5, 128}, { NOTE_A_3, 128}, 116 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_B_4, 128}, 117 { NOTE_C_5, 128}, { NOTE_D_5, 128}, { NOTE_C_4, 128}, 118 { NOTE_G_4, 128}, { NOTE_C_5, 128}, { NOTE_G_4, 128}, 119 { NOTE_F_5, 128}, { NOTE_E_5, 128}, { NOTE_G_3, 128}, 120 { NOTE_G_4, 128}, { NOTE_B_3, 128}, { NOTE_F_4, 128}, 121 { NOTE_E_5, 128}, { NOTE_D_5, 128}, { NOTE_A_3, 128}, 122 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_E_4, 128}, 123 { NOTE_D_5, 128}, { NOTE_C_5, 128}, { NOTE_E_3, 128}, 124 { NOTE_E_4, 128}, { NOTE_E_5, 128}, { NOTE_E_5, 128}, 125 { NOTE_E_6, 128}, { NOTE_E_5, 128}, { NOTE_E_6, 128}, 126 { NOTE_E_5, 128}, { NOTE_E_5, 128}, { NOTE_DS_5, 128}, 127 { NOTE_E_5, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 128 { NOTE_DS_5, 128}, { NOTE_E_5, 128}, { NOTE_DS_6, 128}, 129 { NOTE_E_6, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 130 { NOTE_DS_6, 128}, { NOTE_E_6, 128}, { NOTE_B_5, 128}, 131 { NOTE_D_6, 128}, { NOTE_C_6, 128}, { NOTE_A_3, 128}, 132 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_C_5, 128}, 133 { NOTE_E_5, 128}, { NOTE_A_5, 128}, { NOTE_E_3, 128}, 134 { NOTE_E_4, 128}, { NOTE_GS_4, 128}, { NOTE_E_5, 128}, 135 { NOTE_GS_5, 128}, { NOTE_B_5, 128}, { NOTE_A_3, 128}, 136 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_E_5, 128}, 137 { NOTE_E_6, 128}, { NOTE_DS_6, 128}, { NOTE_E_6, 128}, 138 { NOTE_DS_6, 128}, { NOTE_E_6, 128}, { NOTE_B_5, 128}, 139 { NOTE_D_6, 128}, { NOTE_C_6, 128}, { NOTE_A_3, 128}, 140 { NOTE_E_4, 128}, { NOTE_A_4, 128}, { NOTE_C_5, 128}, 141 { NOTE_E_5, 128}, { NOTE_A_5, 128}, { NOTE_E_3, 128}, 142 { NOTE_E_4, 128}, { NOTE_GS_4, 128}, { NOTE_E_5, 128}, 143 { NOTE_C_6, 128}, { NOTE_B_5, 128}, { NOTE_A_5, 512}, 144 { NOTE_SILENT, 256}, 145 }; 146 147 static struct vidtv_access_unit *vidtv_s302m_access_unit_init(struct vidtv_access_unit *head) 148 { 149 struct vidtv_access_unit *au; 150 151 au = kzalloc(sizeof(*au), GFP_KERNEL); 152 if (!au) 153 return NULL; 154 155 if (head) { 156 while (head->next) 157 head = head->next; 158 159 head->next = au; 160 } 161 162 return au; 163 } 164 165 static void vidtv_s302m_access_unit_destroy(struct vidtv_encoder *e) 166 { 167 struct vidtv_access_unit *head = e->access_units; 168 struct vidtv_access_unit *tmp = NULL; 169 170 while (head) { 171 tmp = head; 172 head = head->next; 173 kfree(tmp); 174 } 175 176 e->access_units = NULL; 177 } 178 179 static void vidtv_s302m_alloc_au(struct vidtv_encoder *e) 180 { 181 struct vidtv_access_unit *sync_au = NULL; 182 struct vidtv_access_unit *temp = NULL; 183 184 if (e->sync && e->sync->is_video_encoder) { 185 sync_au = e->sync->access_units; 186 187 while (sync_au) { 188 temp = vidtv_s302m_access_unit_init(e->access_units); 189 if (!e->access_units) 190 e->access_units = temp; 191 192 sync_au = sync_au->next; 193 } 194 195 return; 196 } 197 198 e->access_units = vidtv_s302m_access_unit_init(NULL); 199 } 200 201 static void 202 vidtv_s302m_compute_sample_count_from_video(struct vidtv_encoder *e) 203 { 204 struct vidtv_access_unit *sync_au = e->sync->access_units; 205 struct vidtv_access_unit *au = e->access_units; 206 u32 sample_duration_usecs; 207 u32 vau_duration_usecs; 208 u32 s; 209 210 vau_duration_usecs = USEC_PER_SEC / e->sync->sampling_rate_hz; 211 sample_duration_usecs = USEC_PER_SEC / e->sampling_rate_hz; 212 213 while (au && sync_au) { 214 s = DIV_ROUND_UP(vau_duration_usecs, sample_duration_usecs); 215 au->num_samples = s; 216 au = au->next; 217 sync_au = sync_au->next; 218 } 219 } 220 221 static void vidtv_s302m_compute_pts_from_video(struct vidtv_encoder *e) 222 { 223 struct vidtv_access_unit *au = e->access_units; 224 struct vidtv_access_unit *sync_au = e->sync->access_units; 225 226 /* use the same pts from the video access unit*/ 227 while (au && sync_au) { 228 au->pts = sync_au->pts; 229 au = au->next; 230 sync_au = sync_au->next; 231 } 232 } 233 234 static u16 vidtv_s302m_get_sample(struct vidtv_encoder *e) 235 { 236 u16 sample; 237 int pos; 238 struct vidtv_s302m_ctx *ctx = e->ctx; 239 240 if (!e->src_buf) { 241 /* 242 * Simple tone generator: play the tones at the 243 * beethoven_fur_elise array. 244 */ 245 if (ctx->last_duration <= 0) { 246 if (e->src_buf_offset >= ARRAY_SIZE(beethoven_fur_elise)) 247 e->src_buf_offset = 0; 248 249 ctx->last_tone = beethoven_fur_elise[e->src_buf_offset].note; 250 ctx->last_duration = beethoven_fur_elise[e->src_buf_offset].duration * 251 S302M_SAMPLING_RATE_HZ / COMPASS / 5; 252 e->src_buf_offset++; 253 ctx->note_offset = 0; 254 } else { 255 ctx->last_duration--; 256 } 257 258 /* Handle pause notes */ 259 if (!ctx->last_tone) 260 return 0x8000; 261 262 pos = (2 * PI * ctx->note_offset * ctx->last_tone) / S302M_SAMPLING_RATE_HZ; 263 ctx->note_offset++; 264 265 return (fixp_sin32(pos % (2 * PI)) >> 16) + 0x8000; 266 } 267 268 /* bug somewhere */ 269 if (e->src_buf_offset > e->src_buf_sz) { 270 pr_err_ratelimited("overflow detected: %d > %d, wrapping.\n", 271 e->src_buf_offset, 272 e->src_buf_sz); 273 274 e->src_buf_offset = 0; 275 } 276 277 if (e->src_buf_offset >= e->src_buf_sz) { 278 /* let the source know we are out of data */ 279 if (e->last_sample_cb) 280 e->last_sample_cb(e->sample_count); 281 282 e->src_buf_offset = 0; 283 } 284 285 sample = *(u16 *)(e->src_buf + e->src_buf_offset); 286 287 return sample; 288 } 289 290 static u32 vidtv_s302m_write_frame(struct vidtv_encoder *e, 291 u16 sample) 292 { 293 struct vidtv_s302m_ctx *ctx = e->ctx; 294 struct vidtv_s302m_frame_16 f = {}; 295 u32 nbytes = 0; 296 297 /* from ffmpeg: see s302enc.c */ 298 299 u8 vucf = ctx->frame_index == 0 ? 0x10 : 0; 300 301 f.data[0] = sample & 0xFF; 302 f.data[1] = (sample & 0xFF00) >> 8; 303 f.data[2] = ((sample & 0x0F) << 4) | vucf; 304 f.data[3] = (sample & 0x0FF0) >> 4; 305 f.data[4] = (sample & 0xF000) >> 12; 306 307 f.data[0] = reverse[f.data[0]]; 308 f.data[1] = reverse[f.data[1]]; 309 f.data[2] = reverse[f.data[2]]; 310 f.data[3] = reverse[f.data[3]]; 311 f.data[4] = reverse[f.data[4]]; 312 313 nbytes += vidtv_memcpy(e->encoder_buf, 314 e->encoder_buf_offset, 315 VIDTV_S302M_BUF_SZ, 316 &f, 317 sizeof(f)); 318 319 e->encoder_buf_offset += nbytes; 320 321 ctx->frame_index++; 322 if (ctx->frame_index >= S302M_BLOCK_SZ) 323 ctx->frame_index = 0; 324 325 return nbytes; 326 } 327 328 static u32 vidtv_s302m_write_h(struct vidtv_encoder *e, u32 p_sz) 329 { 330 struct vidtv_smpte_s302m_es h = {}; 331 u32 nbytes = 0; 332 333 /* 2 channels, ident: 0, 16 bits per sample */ 334 h.bitfield = cpu_to_be32((p_sz << 16)); 335 336 nbytes += vidtv_memcpy(e->encoder_buf, 337 e->encoder_buf_offset, 338 e->encoder_buf_sz, 339 &h, 340 sizeof(h)); 341 342 e->encoder_buf_offset += nbytes; 343 return nbytes; 344 } 345 346 static void vidtv_s302m_write_frames(struct vidtv_encoder *e) 347 { 348 struct vidtv_access_unit *au = e->access_units; 349 struct vidtv_s302m_ctx *ctx = e->ctx; 350 u32 nbytes_per_unit = 0; 351 u32 nbytes = 0; 352 u32 au_sz = 0; 353 u16 sample; 354 u32 j; 355 356 while (au) { 357 au_sz = au->num_samples * 358 sizeof(struct vidtv_s302m_frame_16); 359 360 nbytes_per_unit = vidtv_s302m_write_h(e, au_sz); 361 362 for (j = 0; j < au->num_samples; ++j) { 363 sample = vidtv_s302m_get_sample(e); 364 nbytes_per_unit += vidtv_s302m_write_frame(e, sample); 365 366 if (e->src_buf) 367 e->src_buf_offset += sizeof(u16); 368 369 e->sample_count++; 370 } 371 372 au->nbytes = nbytes_per_unit; 373 374 if (au_sz + sizeof(struct vidtv_smpte_s302m_es) != nbytes_per_unit) { 375 pr_warn_ratelimited("write size was %u, expected %zu\n", 376 nbytes_per_unit, 377 au_sz + sizeof(struct vidtv_smpte_s302m_es)); 378 } 379 380 nbytes += nbytes_per_unit; 381 au->offset = nbytes - nbytes_per_unit; 382 383 nbytes_per_unit = 0; 384 ctx->au_count++; 385 386 au = au->next; 387 } 388 } 389 390 static void *vidtv_s302m_encode(struct vidtv_encoder *e) 391 { 392 struct vidtv_s302m_ctx *ctx = e->ctx; 393 394 /* 395 * According to SMPTE 302M, an audio access unit is specified as those 396 * AES3 words that are associated with a corresponding video frame. 397 * Therefore, there is one audio access unit for every video access unit 398 * in the corresponding video encoder ('sync'), using the same values 399 * for PTS as used by the video encoder. 400 * 401 * Assuming that it is also possible to send audio without any 402 * associated video, as in a radio-like service, a single audio access unit 403 * is created with values for 'num_samples' and 'pts' taken empirically from 404 * ffmpeg 405 */ 406 407 vidtv_s302m_access_unit_destroy(e); 408 vidtv_s302m_alloc_au(e); 409 410 if (e->sync && e->sync->is_video_encoder) { 411 vidtv_s302m_compute_sample_count_from_video(e); 412 vidtv_s302m_compute_pts_from_video(e); 413 } else { 414 e->access_units->num_samples = FF_S302M_DEFAULT_NUM_FRAMES; 415 e->access_units->pts = (ctx->au_count * FF_S302M_DEFAULT_PTS_INCREMENT) + 416 FF_S302M_DEFAULT_PTS_OFFSET; 417 } 418 419 vidtv_s302m_write_frames(e); 420 421 return e->encoder_buf; 422 } 423 424 static u32 vidtv_s302m_clear(struct vidtv_encoder *e) 425 { 426 struct vidtv_access_unit *au = e->access_units; 427 u32 count = 0; 428 429 while (au) { 430 count++; 431 au = au->next; 432 } 433 434 vidtv_s302m_access_unit_destroy(e); 435 memset(e->encoder_buf, 0, VIDTV_S302M_BUF_SZ); 436 e->encoder_buf_offset = 0; 437 438 return count; 439 } 440 441 struct vidtv_encoder 442 *vidtv_s302m_encoder_init(struct vidtv_s302m_encoder_init_args args) 443 { 444 u32 priv_sz = sizeof(struct vidtv_s302m_ctx); 445 struct vidtv_s302m_ctx *ctx; 446 struct vidtv_encoder *e; 447 448 e = kzalloc(sizeof(*e), GFP_KERNEL); 449 if (!e) 450 return NULL; 451 452 e->id = S302M; 453 454 if (args.name) 455 e->name = kstrdup(args.name, GFP_KERNEL); 456 457 e->encoder_buf = vzalloc(VIDTV_S302M_BUF_SZ); 458 if (!e->encoder_buf) 459 goto out_kfree_e; 460 461 e->encoder_buf_sz = VIDTV_S302M_BUF_SZ; 462 e->encoder_buf_offset = 0; 463 464 e->sample_count = 0; 465 466 e->src_buf = (args.src_buf) ? args.src_buf : NULL; 467 e->src_buf_sz = (args.src_buf) ? args.src_buf_sz : 0; 468 e->src_buf_offset = 0; 469 470 e->is_video_encoder = false; 471 472 ctx = kzalloc(priv_sz, GFP_KERNEL); 473 if (!ctx) 474 goto out_kfree_buf; 475 476 e->ctx = ctx; 477 ctx->last_duration = 0; 478 479 e->encode = vidtv_s302m_encode; 480 e->clear = vidtv_s302m_clear; 481 482 e->es_pid = cpu_to_be16(args.es_pid); 483 e->stream_id = cpu_to_be16(PES_PRIVATE_STREAM_1); 484 485 e->sync = args.sync; 486 e->sampling_rate_hz = S302M_SAMPLING_RATE_HZ; 487 488 e->last_sample_cb = args.last_sample_cb; 489 490 e->destroy = vidtv_s302m_encoder_destroy; 491 492 if (args.head) { 493 while (args.head->next) 494 args.head = args.head->next; 495 496 args.head->next = e; 497 } 498 499 e->next = NULL; 500 501 return e; 502 503 out_kfree_buf: 504 vfree(e->encoder_buf); 505 506 out_kfree_e: 507 kfree(e->name); 508 kfree(e); 509 return NULL; 510 } 511 512 void vidtv_s302m_encoder_destroy(struct vidtv_encoder *e) 513 { 514 if (e->id != S302M) { 515 pr_err_ratelimited("Encoder type mismatch, skipping.\n"); 516 return; 517 } 518 519 vidtv_s302m_access_unit_destroy(e); 520 kfree(e->name); 521 vfree(e->encoder_buf); 522 kfree(e->ctx); 523 kfree(e); 524 } 525