1 /*
2 * Copyright (c) 2012 Michael Niedermayer <michaelni@gmx.at>
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 */
20
21 #include <stdatomic.h>
22
23 #include "frame_thread_encoder.h"
24
25 #include "libavutil/avassert.h"
26 #include "libavutil/cpu.h"
27 #include "libavutil/imgutils.h"
28 #include "libavutil/opt.h"
29 #include "libavutil/thread.h"
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "internal.h"
33 #include "pthread_internal.h"
34 #include "thread.h"
35
36 #define MAX_THREADS 64
37 /* There can be as many as MAX_THREADS + 1 outstanding tasks.
38 * An additional + 1 is needed so that one can distinguish
39 * the case of zero and MAX_THREADS + 1 outstanding tasks modulo
40 * the number of buffers. */
41 #define BUFFER_SIZE (MAX_THREADS + 2)
42
43 typedef struct{
44 AVFrame *indata;
45 AVPacket *outdata;
46 int return_code;
47 int finished;
48 } Task;
49
50 typedef struct{
51 AVCodecContext *parent_avctx;
52 pthread_mutex_t buffer_mutex;
53
54 pthread_mutex_t task_fifo_mutex; /* Used to guard (next_)task_index */
55 pthread_cond_t task_fifo_cond;
56
57 unsigned pthread_init_cnt;
58 unsigned max_tasks;
59 Task tasks[BUFFER_SIZE];
60 pthread_mutex_t finished_task_mutex; /* Guards tasks[i].finished */
61 pthread_cond_t finished_task_cond;
62
63 unsigned next_task_index;
64 unsigned task_index;
65 unsigned finished_task_index;
66
67 pthread_t worker[MAX_THREADS];
68 atomic_int exit;
69 } ThreadContext;
70
71 #define OFF(member) offsetof(ThreadContext, member)
72 DEFINE_OFFSET_ARRAY(ThreadContext, thread_ctx, pthread_init_cnt,
73 (OFF(buffer_mutex), OFF(task_fifo_mutex), OFF(finished_task_mutex)),
74 (OFF(task_fifo_cond), OFF(finished_task_cond)));
75 #undef OFF
76
worker(void * v)77 static void * attribute_align_arg worker(void *v){
78 AVCodecContext *avctx = v;
79 ThreadContext *c = avctx->internal->frame_thread_encoder;
80
81 while (!atomic_load(&c->exit)) {
82 int got_packet = 0, ret;
83 AVPacket *pkt;
84 AVFrame *frame;
85 Task *task;
86 unsigned task_index;
87
88 pthread_mutex_lock(&c->task_fifo_mutex);
89 while (c->next_task_index == c->task_index || atomic_load(&c->exit)) {
90 if (atomic_load(&c->exit)) {
91 pthread_mutex_unlock(&c->task_fifo_mutex);
92 goto end;
93 }
94 pthread_cond_wait(&c->task_fifo_cond, &c->task_fifo_mutex);
95 }
96 task_index = c->next_task_index;
97 c->next_task_index = (c->next_task_index + 1) % c->max_tasks;
98 pthread_mutex_unlock(&c->task_fifo_mutex);
99 /* The main thread ensures that any two outstanding tasks have
100 * different indices, ergo each worker thread owns its element
101 * of c->tasks with the exception of finished, which is shared
102 * with the main thread and guarded by finished_task_mutex. */
103 task = &c->tasks[task_index];
104 frame = task->indata;
105 pkt = task->outdata;
106
107 ret = ffcodec(avctx->codec)->cb.encode(avctx, pkt, frame, &got_packet);
108 if(got_packet) {
109 int ret2 = av_packet_make_refcounted(pkt);
110 if (ret >= 0 && ret2 < 0)
111 ret = ret2;
112 pkt->pts = pkt->dts = frame->pts;
113 } else {
114 pkt->data = NULL;
115 pkt->size = 0;
116 }
117 pthread_mutex_lock(&c->buffer_mutex);
118 av_frame_unref(frame);
119 pthread_mutex_unlock(&c->buffer_mutex);
120 pthread_mutex_lock(&c->finished_task_mutex);
121 task->return_code = ret;
122 task->finished = 1;
123 pthread_cond_signal(&c->finished_task_cond);
124 pthread_mutex_unlock(&c->finished_task_mutex);
125 }
126 end:
127 pthread_mutex_lock(&c->buffer_mutex);
128 avcodec_close(avctx);
129 pthread_mutex_unlock(&c->buffer_mutex);
130 av_freep(&avctx);
131 return NULL;
132 }
133
ff_frame_thread_encoder_init(AVCodecContext * avctx)134 av_cold int ff_frame_thread_encoder_init(AVCodecContext *avctx)
135 {
136 int i=0;
137 ThreadContext *c;
138 AVCodecContext *thread_avctx = NULL;
139 int ret;
140
141 if( !(avctx->thread_type & FF_THREAD_FRAME)
142 || !(avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS))
143 return 0;
144
145 if( !avctx->thread_count
146 && avctx->codec_id == AV_CODEC_ID_MJPEG
147 && !(avctx->flags & AV_CODEC_FLAG_QSCALE)) {
148 av_log(avctx, AV_LOG_DEBUG,
149 "Forcing thread count to 1 for MJPEG encoding, use -thread_type slice "
150 "or a constant quantizer if you want to use multiple cpu cores\n");
151 avctx->thread_count = 1;
152 }
153 if( avctx->thread_count > 1
154 && avctx->codec_id == AV_CODEC_ID_MJPEG
155 && !(avctx->flags & AV_CODEC_FLAG_QSCALE))
156 av_log(avctx, AV_LOG_WARNING,
157 "MJPEG CBR encoding works badly with frame multi-threading, consider "
158 "using -threads 1, -thread_type slice or a constant quantizer.\n");
159
160 if (avctx->codec_id == AV_CODEC_ID_HUFFYUV ||
161 avctx->codec_id == AV_CODEC_ID_FFVHUFF) {
162 int warn = 0;
163 int64_t tmp;
164
165 if (avctx->flags & AV_CODEC_FLAG_PASS1)
166 warn = 1;
167 else if (av_opt_get_int(avctx->priv_data, "context", 0, &tmp) >= 0 &&
168 tmp > 0) {
169 warn = av_opt_get_int(avctx->priv_data, "non_deterministic", 0, &tmp) < 0
170 || !tmp;
171 }
172 // huffyuv does not support these with multiple frame threads currently
173 if (warn) {
174 av_log(avctx, AV_LOG_WARNING,
175 "Forcing thread count to 1 for huffyuv encoding with first pass or context 1\n");
176 avctx->thread_count = 1;
177 }
178 }
179
180 if(!avctx->thread_count) {
181 avctx->thread_count = av_cpu_count();
182 avctx->thread_count = FFMIN(avctx->thread_count, MAX_THREADS);
183 }
184
185 if(avctx->thread_count <= 1)
186 return 0;
187
188 if(avctx->thread_count > MAX_THREADS)
189 return AVERROR(EINVAL);
190
191 av_assert0(!avctx->internal->frame_thread_encoder);
192 c = avctx->internal->frame_thread_encoder = av_mallocz(sizeof(ThreadContext));
193 if(!c)
194 return AVERROR(ENOMEM);
195
196 c->parent_avctx = avctx;
197
198 ret = ff_pthread_init(c, thread_ctx_offsets);
199 if (ret < 0)
200 goto fail;
201 atomic_init(&c->exit, 0);
202
203 c->max_tasks = avctx->thread_count + 2;
204 for (unsigned j = 0; j < c->max_tasks; j++) {
205 if (!(c->tasks[j].indata = av_frame_alloc()) ||
206 !(c->tasks[j].outdata = av_packet_alloc())) {
207 ret = AVERROR(ENOMEM);
208 goto fail;
209 }
210 }
211
212 for(i=0; i<avctx->thread_count ; i++){
213 void *tmpv;
214 thread_avctx = avcodec_alloc_context3(avctx->codec);
215 if (!thread_avctx) {
216 ret = AVERROR(ENOMEM);
217 goto fail;
218 }
219 tmpv = thread_avctx->priv_data;
220 *thread_avctx = *avctx;
221 thread_avctx->priv_data = tmpv;
222 thread_avctx->internal = NULL;
223 thread_avctx->hw_frames_ctx = NULL;
224 ret = av_opt_copy(thread_avctx, avctx);
225 if (ret < 0)
226 goto fail;
227 if (avctx->codec->priv_class) {
228 ret = av_opt_copy(thread_avctx->priv_data, avctx->priv_data);
229 if (ret < 0)
230 goto fail;
231 }
232 thread_avctx->thread_count = 1;
233 thread_avctx->active_thread_type &= ~FF_THREAD_FRAME;
234
235 if ((ret = avcodec_open2(thread_avctx, avctx->codec, NULL)) < 0)
236 goto fail;
237 av_assert0(!thread_avctx->internal->frame_thread_encoder);
238 thread_avctx->internal->frame_thread_encoder = c;
239 if ((ret = pthread_create(&c->worker[i], NULL, worker, thread_avctx))) {
240 ret = AVERROR(ret);
241 goto fail;
242 }
243 }
244
245 avctx->active_thread_type = FF_THREAD_FRAME;
246
247 return 0;
248 fail:
249 avcodec_close(thread_avctx);
250 av_freep(&thread_avctx);
251 avctx->thread_count = i;
252 av_log(avctx, AV_LOG_ERROR, "ff_frame_thread_encoder_init failed\n");
253 ff_frame_thread_encoder_free(avctx);
254 return ret;
255 }
256
ff_frame_thread_encoder_free(AVCodecContext * avctx)257 av_cold void ff_frame_thread_encoder_free(AVCodecContext *avctx)
258 {
259 ThreadContext *c= avctx->internal->frame_thread_encoder;
260
261 /* In case initializing the mutexes/condition variables failed,
262 * they must not be used. In this case the thread_count is zero
263 * as no thread has been initialized yet. */
264 if (avctx->thread_count > 0) {
265 pthread_mutex_lock(&c->task_fifo_mutex);
266 atomic_store(&c->exit, 1);
267 pthread_cond_broadcast(&c->task_fifo_cond);
268 pthread_mutex_unlock(&c->task_fifo_mutex);
269
270 for (int i = 0; i < avctx->thread_count; i++)
271 pthread_join(c->worker[i], NULL);
272 }
273
274 for (unsigned i = 0; i < c->max_tasks; i++) {
275 av_frame_free(&c->tasks[i].indata);
276 av_packet_free(&c->tasks[i].outdata);
277 }
278
279 ff_pthread_free(c, thread_ctx_offsets);
280 av_freep(&avctx->internal->frame_thread_encoder);
281 }
282
ff_thread_video_encode_frame(AVCodecContext * avctx,AVPacket * pkt,AVFrame * frame,int * got_packet_ptr)283 int ff_thread_video_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
284 AVFrame *frame, int *got_packet_ptr)
285 {
286 ThreadContext *c = avctx->internal->frame_thread_encoder;
287 Task *outtask;
288
289 av_assert1(!*got_packet_ptr);
290
291 if(frame){
292 av_frame_move_ref(c->tasks[c->task_index].indata, frame);
293
294 pthread_mutex_lock(&c->task_fifo_mutex);
295 c->task_index = (c->task_index + 1) % c->max_tasks;
296 pthread_cond_signal(&c->task_fifo_cond);
297 pthread_mutex_unlock(&c->task_fifo_mutex);
298 }
299
300 outtask = &c->tasks[c->finished_task_index];
301 pthread_mutex_lock(&c->finished_task_mutex);
302 /* The access to task_index in the following code is ok,
303 * because it is only ever changed by the main thread. */
304 if (c->task_index == c->finished_task_index ||
305 (frame && !outtask->finished &&
306 (c->task_index - c->finished_task_index + c->max_tasks) % c->max_tasks <= avctx->thread_count)) {
307 pthread_mutex_unlock(&c->finished_task_mutex);
308 return 0;
309 }
310 while (!outtask->finished) {
311 pthread_cond_wait(&c->finished_task_cond, &c->finished_task_mutex);
312 }
313 pthread_mutex_unlock(&c->finished_task_mutex);
314 /* We now own outtask completely: No worker thread touches it any more,
315 * because there is no outstanding task with this index. */
316 outtask->finished = 0;
317 av_packet_move_ref(pkt, outtask->outdata);
318 if(pkt->data)
319 *got_packet_ptr = 1;
320 c->finished_task_index = (c->finished_task_index + 1) % c->max_tasks;
321
322 return outtask->return_code;
323 }
324