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
vidtv_s302m_access_unit_init(struct vidtv_access_unit * head)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
vidtv_s302m_access_unit_destroy(struct vidtv_encoder * e)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
vidtv_s302m_alloc_au(struct vidtv_encoder * e)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
vidtv_s302m_compute_sample_count_from_video(struct vidtv_encoder * e)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
vidtv_s302m_compute_pts_from_video(struct vidtv_encoder * e)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
vidtv_s302m_get_sample(struct vidtv_encoder * e)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
vidtv_s302m_write_frame(struct vidtv_encoder * e,u16 sample)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
vidtv_s302m_write_h(struct vidtv_encoder * e,u32 p_sz)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
vidtv_s302m_write_frames(struct vidtv_encoder * e)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
vidtv_s302m_encode(struct vidtv_encoder * e)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
vidtv_s302m_clear(struct vidtv_encoder * e)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
vidtv_s302m_encoder_init(struct vidtv_s302m_encoder_init_args args)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 e->encoder_buf_sz = VIDTV_S302M_BUF_SZ;
459 e->encoder_buf_offset = 0;
460
461 e->sample_count = 0;
462
463 e->src_buf = (args.src_buf) ? args.src_buf : NULL;
464 e->src_buf_sz = (args.src_buf) ? args.src_buf_sz : 0;
465 e->src_buf_offset = 0;
466
467 e->is_video_encoder = false;
468
469 ctx = kzalloc(priv_sz, GFP_KERNEL);
470 if (!ctx) {
471 kfree(e);
472 return NULL;
473 }
474
475 e->ctx = ctx;
476 ctx->last_duration = 0;
477
478 e->encode = vidtv_s302m_encode;
479 e->clear = vidtv_s302m_clear;
480
481 e->es_pid = cpu_to_be16(args.es_pid);
482 e->stream_id = cpu_to_be16(PES_PRIVATE_STREAM_1);
483
484 e->sync = args.sync;
485 e->sampling_rate_hz = S302M_SAMPLING_RATE_HZ;
486
487 e->last_sample_cb = args.last_sample_cb;
488
489 e->destroy = vidtv_s302m_encoder_destroy;
490
491 if (args.head) {
492 while (args.head->next)
493 args.head = args.head->next;
494
495 args.head->next = e;
496 }
497
498 e->next = NULL;
499
500 return e;
501 }
502
vidtv_s302m_encoder_destroy(struct vidtv_encoder * e)503 void vidtv_s302m_encoder_destroy(struct vidtv_encoder *e)
504 {
505 if (e->id != S302M) {
506 pr_err_ratelimited("Encoder type mismatch, skipping.\n");
507 return;
508 }
509
510 vidtv_s302m_access_unit_destroy(e);
511 kfree(e->name);
512 vfree(e->encoder_buf);
513 kfree(e->ctx);
514 kfree(e);
515 }
516