lavc: add MMAL hardware decoder wrapper
[libav.git] / libavcodec / mmaldec.c
1 /*
2 * MMAL Video Decoder
3 * Copyright (c) 2015 Rodger Combs
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * MMAL Video Decoder
25 */
26
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "libavutil/atomic.h"
30 #include "libavutil/avassert.h"
31 #include "libavutil/buffer.h"
32 #include "libavutil/common.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/log.h"
35
36 #include <bcm_host.h>
37 #include <interface/mmal/mmal.h>
38 #include <interface/mmal/util/mmal_util.h>
39 #include <interface/mmal/util/mmal_util_params.h>
40 #include <interface/mmal/util/mmal_default_components.h>
41
42 typedef struct FFBufferEntry {
43 AVBufferRef *ref;
44 void *data;
45 size_t length;
46 int64_t pts, dts;
47 int flags;
48 struct FFBufferEntry *next;
49 } FFBufferEntry;
50
51 // MMAL_POOL_T destroys all of its MMAL_BUFFER_HEADER_Ts. If we want correct
52 // refcounting for AVFrames, we can free the MMAL_POOL_T only after all AVFrames
53 // have been unreferenced.
54 typedef struct FFPoolRef {
55 volatile int refcount;
56 MMAL_POOL_T *pool;
57 } FFPoolRef;
58
59 typedef struct FFBufferRef {
60 MMAL_BUFFER_HEADER_T *buffer;
61 FFPoolRef *pool;
62 } FFBufferRef;
63
64 typedef struct MMALDecodeContext {
65 AVClass *av_class;
66 int extra_buffers;
67
68 AVBitStreamFilterContext *bsfc;
69
70 MMAL_COMPONENT_T *decoder;
71 MMAL_QUEUE_T *queue_decoded_frames;
72 MMAL_POOL_T *pool_in;
73 FFPoolRef *pool_out;
74
75 // Waiting input packets. Because the libavcodec API requires decoding and
76 // returning packets in lockstep, it can happen that queue_decoded_frames
77 // contains almost all surfaces - then the decoder input queue can quickly
78 // fill up and won't accept new input either. Without consuming input, the
79 // libavcodec API can't return new frames, and we have a logical deadlock.
80 // This is avoided by queuing such buffers here.
81 FFBufferEntry *waiting_buffers, *waiting_buffers_tail;
82
83 int64_t packets_sent;
84 int64_t frames_output;
85 int eos_received;
86 int eos_sent;
87 } MMALDecodeContext;
88
89 // Assume decoder is guaranteed to produce output after at least this many
90 // packets (where each packet contains 1 frame).
91 #define MAX_DELAYED_FRAMES 16
92
93 static void ffmmal_poolref_unref(FFPoolRef *ref)
94 {
95 if (ref && avpriv_atomic_int_add_and_fetch(&ref->refcount, -1) == 0) {
96 mmal_pool_destroy(ref->pool);
97 av_free(ref);
98 }
99 }
100
101 static void ffmmal_release_frame(void *opaque, uint8_t *data)
102 {
103 FFBufferRef *ref = (void *)data;
104
105 mmal_buffer_header_release(ref->buffer);
106 ffmmal_poolref_unref(ref->pool);
107
108 av_free(ref);
109 }
110
111 // Setup frame with a new reference to buffer. The buffer must have been
112 // allocated from the given pool.
113 static int ffmmal_set_ref(AVFrame *frame, FFPoolRef *pool,
114 MMAL_BUFFER_HEADER_T *buffer)
115 {
116 FFBufferRef *ref = av_mallocz(sizeof(*ref));
117 if (!ref)
118 return AVERROR(ENOMEM);
119
120 ref->pool = pool;
121 ref->buffer = buffer;
122
123 frame->buf[0] = av_buffer_create((void *)ref, sizeof(*ref),
124 ffmmal_release_frame, NULL,
125 AV_BUFFER_FLAG_READONLY);
126 if (!frame->buf[0]) {
127 av_free(ref);
128 return AVERROR(ENOMEM);
129 }
130
131 avpriv_atomic_int_add_and_fetch(&ref->pool->refcount, 1);
132 mmal_buffer_header_acquire(buffer);
133
134 frame->format = AV_PIX_FMT_MMAL;
135 frame->data[3] = (uint8_t *)ref->buffer;
136 return 0;
137 }
138
139 static void ffmmal_stop_decoder(AVCodecContext *avctx)
140 {
141 MMALDecodeContext *ctx = avctx->priv_data;
142 MMAL_COMPONENT_T *decoder = ctx->decoder;
143 MMAL_BUFFER_HEADER_T *buffer;
144
145 mmal_port_disable(decoder->input[0]);
146 mmal_port_disable(decoder->output[0]);
147 mmal_port_disable(decoder->control);
148
149 mmal_port_flush(decoder->input[0]);
150 mmal_port_flush(decoder->output[0]);
151 mmal_port_flush(decoder->control);
152
153 while ((buffer = mmal_queue_get(ctx->queue_decoded_frames)))
154 mmal_buffer_header_release(buffer);
155
156 while (ctx->waiting_buffers) {
157 FFBufferEntry *buffer = ctx->waiting_buffers;
158
159 ctx->waiting_buffers = buffer->next;
160
161 av_buffer_unref(&buffer->ref);
162 av_free(buffer);
163 }
164 ctx->waiting_buffers_tail = NULL;
165
166 ctx->frames_output = ctx->eos_received = ctx->eos_sent = ctx->packets_sent = 0;
167 }
168
169 static av_cold int ffmmal_close_decoder(AVCodecContext *avctx)
170 {
171 MMALDecodeContext *ctx = avctx->priv_data;
172
173 if (ctx->decoder)
174 ffmmal_stop_decoder(avctx);
175
176 mmal_component_destroy(ctx->decoder);
177 ctx->decoder = NULL;
178 mmal_queue_destroy(ctx->queue_decoded_frames);
179 mmal_pool_destroy(ctx->pool_in);
180 ffmmal_poolref_unref(ctx->pool_out);
181
182 if (ctx->bsfc)
183 av_bitstream_filter_close(ctx->bsfc);
184
185 return 0;
186 }
187
188 static void input_callback(MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buffer)
189 {
190 if (!buffer->cmd) {
191 AVBufferRef *buf = buffer->user_data;
192 av_buffer_unref(&buf);
193 }
194 mmal_buffer_header_release(buffer);
195 }
196
197 static void output_callback(MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buffer)
198 {
199 AVCodecContext *avctx = (AVCodecContext*)port->userdata;
200 MMALDecodeContext *ctx = avctx->priv_data;
201
202 mmal_queue_put(ctx->queue_decoded_frames, buffer);
203 }
204
205 static void control_port_cb(MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buffer)
206 {
207 AVCodecContext *avctx = (AVCodecContext*)port->userdata;
208 MMAL_STATUS_T status;
209
210 if (buffer->cmd == MMAL_EVENT_ERROR) {
211 status = *(uint32_t *)buffer->data;
212 av_log(avctx, AV_LOG_ERROR, "MMAL error %d on control port\n", (int)status);
213 } else {
214 char s[20];
215 av_get_codec_tag_string(s, sizeof(s), buffer->cmd);
216 av_log(avctx, AV_LOG_WARNING, "Unknown MMAL event %s on control port\n", s);
217 }
218
219 mmal_buffer_header_release(buffer);
220 }
221
222 // Feed free output buffers to the decoder.
223 static int ffmmal_fill_output_port(AVCodecContext *avctx)
224 {
225 MMALDecodeContext *ctx = avctx->priv_data;
226 MMAL_BUFFER_HEADER_T *buffer;
227 MMAL_STATUS_T status;
228
229 if (!ctx->pool_out)
230 return AVERROR_UNKNOWN; // format change code failed with OOM previously
231
232 while ((buffer = mmal_queue_get(ctx->pool_out->pool->queue))) {
233 if ((status = mmal_port_send_buffer(ctx->decoder->output[0], buffer))) {
234 mmal_buffer_header_release(buffer);
235 av_log(avctx, AV_LOG_ERROR, "MMAL error %d when sending output buffer.\n", (int)status);
236 return AVERROR_UNKNOWN;
237 }
238 }
239
240 return 0;
241 }
242
243 static enum AVColorSpace ffmmal_csp_to_av_csp(MMAL_FOURCC_T fourcc)
244 {
245 switch (fourcc) {
246 case MMAL_COLOR_SPACE_BT470_2_BG:
247 case MMAL_COLOR_SPACE_BT470_2_M:
248 case MMAL_COLOR_SPACE_ITUR_BT601: return AVCOL_SPC_BT470BG;
249 case MMAL_COLOR_SPACE_ITUR_BT709: return AVCOL_SPC_BT709;
250 case MMAL_COLOR_SPACE_FCC: return AVCOL_SPC_FCC;
251 case MMAL_COLOR_SPACE_SMPTE240M: return AVCOL_SPC_SMPTE240M;
252 default: return AVCOL_SPC_UNSPECIFIED;
253 }
254 }
255
256 static int ffmal_update_format(AVCodecContext *avctx)
257 {
258 MMALDecodeContext *ctx = avctx->priv_data;
259 MMAL_STATUS_T status;
260 int ret = 0;
261 MMAL_COMPONENT_T *decoder = ctx->decoder;
262 MMAL_ES_FORMAT_T *format_out = decoder->output[0]->format;
263
264 ffmmal_poolref_unref(ctx->pool_out);
265 if (!(ctx->pool_out = av_mallocz(sizeof(*ctx->pool_out)))) {
266 ret = AVERROR(ENOMEM);
267 goto fail;
268 }
269 ctx->pool_out->refcount = 1;
270
271 if (!format_out)
272 goto fail;
273
274 if ((status = mmal_port_parameter_set_uint32(decoder->output[0], MMAL_PARAMETER_EXTRA_BUFFERS, ctx->extra_buffers)))
275 goto fail;
276
277 if (avctx->pix_fmt == AV_PIX_FMT_MMAL) {
278 format_out->encoding = MMAL_ENCODING_OPAQUE;
279 } else {
280 format_out->encoding_variant = format_out->encoding = MMAL_ENCODING_I420;
281 }
282
283 if ((status = mmal_port_format_commit(decoder->output[0])))
284 goto fail;
285
286 if ((ret = ff_set_dimensions(avctx, format_out->es->video.crop.x + format_out->es->video.crop.width,
287 format_out->es->video.crop.y + format_out->es->video.crop.height)) < 0)
288 goto fail;
289
290 if (format_out->es->video.par.num && format_out->es->video.par.den) {
291 avctx->sample_aspect_ratio.num = format_out->es->video.par.num;
292 avctx->sample_aspect_ratio.den = format_out->es->video.par.den;
293 }
294
295 avctx->colorspace = ffmmal_csp_to_av_csp(format_out->es->video.color_space);
296
297 decoder->output[0]->buffer_size =
298 FFMAX(decoder->output[0]->buffer_size_min, decoder->output[0]->buffer_size_recommended);
299 decoder->output[0]->buffer_num =
300 FFMAX(decoder->output[0]->buffer_num_min, decoder->output[0]->buffer_num_recommended) + ctx->extra_buffers;
301 ctx->pool_out->pool = mmal_pool_create(decoder->output[0]->buffer_num,
302 decoder->output[0]->buffer_size);
303 if (!ctx->pool_out->pool) {
304 ret = AVERROR(ENOMEM);
305 goto fail;
306 }
307
308 return 0;
309
310 fail:
311 return ret < 0 ? ret : AVERROR_UNKNOWN;
312 }
313
314 static av_cold int ffmmal_init_decoder(AVCodecContext *avctx)
315 {
316 MMALDecodeContext *ctx = avctx->priv_data;
317 MMAL_STATUS_T status;
318 MMAL_ES_FORMAT_T *format_in;
319 MMAL_COMPONENT_T *decoder;
320 int ret = 0;
321
322 bcm_host_init();
323
324 if ((ret = ff_get_format(avctx, avctx->codec->pix_fmts)) < 0)
325 return ret;
326
327 avctx->pix_fmt = ret;
328
329 if ((status = mmal_component_create(MMAL_COMPONENT_DEFAULT_VIDEO_DECODER, &ctx->decoder)))
330 goto fail;
331
332 decoder = ctx->decoder;
333
334 format_in = decoder->input[0]->format;
335 format_in->type = MMAL_ES_TYPE_VIDEO;
336 format_in->encoding = MMAL_ENCODING_H264;
337 format_in->es->video.width = FFALIGN(avctx->width, 32);
338 format_in->es->video.height = FFALIGN(avctx->height, 16);
339 format_in->es->video.crop.width = avctx->width;
340 format_in->es->video.crop.height = avctx->height;
341 format_in->es->video.frame_rate.num = 24000;
342 format_in->es->video.frame_rate.den = 1001;
343 format_in->es->video.par.num = avctx->sample_aspect_ratio.num;
344 format_in->es->video.par.den = avctx->sample_aspect_ratio.den;
345 format_in->flags = MMAL_ES_FORMAT_FLAG_FRAMED;
346
347 if (avctx->codec->id == AV_CODEC_ID_H264 && avctx->extradata && avctx->extradata[0] == 1) {
348 uint8_t *dummy_p;
349 int dummy_int;
350 ctx->bsfc = av_bitstream_filter_init("h264_mp4toannexb");
351 if (!ctx->bsfc) {
352 av_log(avctx, AV_LOG_ERROR, "Cannot open the h264_mp4toannexb BSF!\n");
353 ret = AVERROR(ENOSYS);
354 goto fail;
355 }
356 av_bitstream_filter_filter(ctx->bsfc, avctx, NULL, &dummy_p, &dummy_int, NULL, 0, 0);
357 }
358
359 if (avctx->extradata_size) {
360 if ((status = mmal_format_extradata_alloc(format_in, avctx->extradata_size)))
361 goto fail;
362 format_in->extradata_size = avctx->extradata_size;
363 memcpy(format_in->extradata, avctx->extradata, format_in->extradata_size);
364 }
365
366 if ((status = mmal_port_format_commit(decoder->input[0])))
367 goto fail;
368
369 decoder->input[0]->buffer_num =
370 FFMAX(decoder->input[0]->buffer_num_min, 20);
371 decoder->input[0]->buffer_size =
372 FFMAX(decoder->input[0]->buffer_size_min, 512 * 1024);
373 ctx->pool_in = mmal_pool_create(decoder->input[0]->buffer_num, 0);
374 if (!ctx->pool_in) {
375 ret = AVERROR(ENOMEM);
376 goto fail;
377 }
378
379 if ((ret = ffmal_update_format(avctx)) < 0)
380 goto fail;
381
382 ctx->queue_decoded_frames = mmal_queue_create();
383 if (!ctx->queue_decoded_frames)
384 goto fail;
385
386 decoder->input[0]->userdata = (void*)avctx;
387 decoder->output[0]->userdata = (void*)avctx;
388 decoder->control->userdata = (void*)avctx;
389
390 if ((status = mmal_port_enable(decoder->control, control_port_cb)))
391 goto fail;
392 if ((status = mmal_port_enable(decoder->input[0], input_callback)))
393 goto fail;
394 if ((status = mmal_port_enable(decoder->output[0], output_callback)))
395 goto fail;
396
397 if ((status = mmal_component_enable(decoder)))
398 goto fail;
399
400 return 0;
401
402 fail:
403 ffmmal_close_decoder(avctx);
404 return ret < 0 ? ret : AVERROR_UNKNOWN;
405 }
406
407 static void ffmmal_flush(AVCodecContext *avctx)
408 {
409 MMALDecodeContext *ctx = avctx->priv_data;
410 MMAL_COMPONENT_T *decoder = ctx->decoder;
411 MMAL_STATUS_T status;
412
413 ffmmal_stop_decoder(avctx);
414
415 if ((status = mmal_port_enable(decoder->control, control_port_cb)))
416 goto fail;
417 if ((status = mmal_port_enable(decoder->input[0], input_callback)))
418 goto fail;
419 if ((status = mmal_port_enable(decoder->output[0], output_callback)))
420 goto fail;
421
422 return;
423
424 fail:
425 av_log(avctx, AV_LOG_ERROR, "MMAL flush error: %i\n", (int)status);
426 }
427
428 // Split packets and add them to the waiting_buffers list. We don't queue them
429 // immediately, because it can happen that the decoder is temporarily blocked
430 // (due to us not reading/returning enough output buffers) and won't accept
431 // new input. (This wouldn't be an issue if MMAL input buffers always were
432 // complete frames - then the input buffer just would have to be big enough.)
433 static int ffmmal_add_packet(AVCodecContext *avctx, AVPacket *avpkt)
434 {
435 MMALDecodeContext *ctx = avctx->priv_data;
436 AVBufferRef *buf = NULL;
437 int size = 0;
438 uint8_t *data = (uint8_t *)"";
439 uint8_t *start;
440 int ret = 0;
441
442 ctx->packets_sent++;
443
444 if (avpkt->size) {
445 if (ctx->bsfc) {
446 uint8_t *tmp_data;
447 int tmp_size;
448 if ((ret = av_bitstream_filter_filter(ctx->bsfc, avctx, NULL,
449 &tmp_data, &tmp_size,
450 avpkt->data, avpkt->size,
451 avpkt->flags & AV_PKT_FLAG_KEY)) < 0)
452 goto done;
453 buf = av_buffer_create(tmp_data, tmp_size, NULL, NULL, 0);
454 } else {
455 if (avpkt->buf) {
456 buf = av_buffer_ref(avpkt->buf);
457 } else {
458 buf = av_buffer_alloc(avpkt->size);
459 if (buf)
460 memcpy(buf->data, avpkt->data, avpkt->size);
461 }
462 }
463 if (!buf) {
464 ret = AVERROR(ENOMEM);
465 goto done;
466 }
467 size = buf->size;
468 data = buf->data;
469 }
470
471 start = data;
472
473 do {
474 FFBufferEntry *buffer = av_mallocz(sizeof(*buffer));
475 if (!buffer) {
476 ret = AVERROR(ENOMEM);
477 goto done;
478 }
479
480 buffer->data = data;
481 buffer->length = FFMIN(size, ctx->decoder->input[0]->buffer_size);
482
483 if (data == start)
484 buffer->flags |= MMAL_BUFFER_HEADER_FLAG_FRAME_START;
485
486 data += buffer->length;
487 size -= buffer->length;
488
489 buffer->pts = avpkt->pts == AV_NOPTS_VALUE ? MMAL_TIME_UNKNOWN : avpkt->pts;
490 buffer->dts = avpkt->dts == AV_NOPTS_VALUE ? MMAL_TIME_UNKNOWN : avpkt->dts;
491
492 if (!size)
493 buffer->flags |= MMAL_BUFFER_HEADER_FLAG_FRAME_END;
494
495 if (!buffer->length) {
496 buffer->flags |= MMAL_BUFFER_HEADER_FLAG_EOS;
497 ctx->eos_sent = 1;
498 }
499
500 if (buf) {
501 buffer->ref = av_buffer_ref(buf);
502 if (!buffer->ref) {
503 av_free(buffer);
504 ret = AVERROR(ENOMEM);
505 goto done;
506 }
507 }
508
509 // Insert at end of the list
510 if (!ctx->waiting_buffers)
511 ctx->waiting_buffers = buffer;
512 if (ctx->waiting_buffers_tail)
513 ctx->waiting_buffers_tail->next = buffer;
514 ctx->waiting_buffers_tail = buffer;
515 } while (size);
516
517 done:
518 av_buffer_unref(&buf);
519 return ret;
520 }
521
522 // Move prepared/split packets from waiting_buffers to the MMAL decoder.
523 static int ffmmal_fill_input_port(AVCodecContext *avctx)
524 {
525 MMALDecodeContext *ctx = avctx->priv_data;
526
527 while (ctx->waiting_buffers) {
528 MMAL_BUFFER_HEADER_T *mbuffer;
529 FFBufferEntry *buffer;
530 MMAL_STATUS_T status;
531
532 mbuffer = mmal_queue_get(ctx->pool_in->queue);
533 if (!mbuffer)
534 return 0;
535
536 buffer = ctx->waiting_buffers;
537
538 mmal_buffer_header_reset(mbuffer);
539 mbuffer->cmd = 0;
540 mbuffer->pts = buffer->pts;
541 mbuffer->dts = buffer->dts;
542 mbuffer->flags = buffer->flags;
543 mbuffer->data = buffer->data;
544 mbuffer->length = buffer->length;
545 mbuffer->user_data = buffer->ref;
546 mbuffer->alloc_size = ctx->decoder->input[0]->buffer_size;
547
548 if ((status = mmal_port_send_buffer(ctx->decoder->input[0], mbuffer))) {
549 mmal_buffer_header_release(mbuffer);
550 av_buffer_unref(&buffer->ref);
551 }
552
553 // Remove from start of the list
554 ctx->waiting_buffers = buffer->next;
555 if (ctx->waiting_buffers_tail == buffer)
556 ctx->waiting_buffers_tail = NULL;
557 av_free(buffer);
558
559 if (status) {
560 av_log(avctx, AV_LOG_ERROR, "MMAL error %d when sending input\n", (int)status);
561 return AVERROR_UNKNOWN;
562 }
563 }
564
565 return 0;
566 }
567
568 static int ffmal_copy_frame(AVCodecContext *avctx, AVFrame *frame,
569 MMAL_BUFFER_HEADER_T *buffer)
570 {
571 MMALDecodeContext *ctx = avctx->priv_data;
572 int ret = 0;
573
574 if (avctx->pix_fmt == AV_PIX_FMT_MMAL) {
575 if (!ctx->pool_out)
576 return AVERROR_UNKNOWN; // format change code failed with OOM previously
577
578 if ((ret = ff_decode_frame_props(avctx, frame)) < 0)
579 goto done;
580
581 if ((ret = ffmmal_set_ref(frame, ctx->pool_out, buffer)) < 0)
582 goto done;
583 } else {
584 int w = FFALIGN(avctx->width, 32);
585 int h = FFALIGN(avctx->height, 16);
586 char *ptr;
587 int plane;
588 int i;
589
590 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
591 goto done;
592
593 ptr = buffer->data + buffer->type->video.offset[0];
594 for (i = 0; i < avctx->height; i++)
595 memcpy(frame->data[0] + frame->linesize[0] * i, ptr + w * i, avctx->width);
596
597 ptr += w * h;
598
599 for (plane = 1; plane < 3; plane++) {
600 for (i = 0; i < avctx->height / 2; i++)
601 memcpy(frame->data[plane] + frame->linesize[plane] * i, ptr + w / 2 * i, (avctx->width + 1) / 2);
602 ptr += w / 2 * h / 2;
603 }
604 }
605
606 if (buffer->pts != MMAL_TIME_UNKNOWN) {
607 frame->pkt_pts = buffer->pts;
608 frame->pts = buffer->pts;
609 }
610
611 done:
612 return ret;
613 }
614
615 // Fetch a decoded buffer and place it into the frame parameter.
616 static int ffmmal_read_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame)
617 {
618 MMALDecodeContext *ctx = avctx->priv_data;
619 MMAL_BUFFER_HEADER_T *buffer = NULL;
620 MMAL_STATUS_T status = 0;
621 int ret = 0;
622
623 if (ctx->eos_received)
624 goto done;
625
626 while (1) {
627 // To ensure decoding in lockstep with a constant delay between fed packets
628 // and output frames, we always wait until an output buffer is available.
629 // Except during start we don't know after how many input packets the decoder
630 // is going to return the first buffer, and we can't distinguish decoder
631 // being busy from decoder waiting for input. So just poll at the start and
632 // keep feeding new data to the buffer.
633 // We are pretty sure the decoder will produce output if we sent more input
634 // frames than what a h264 decoder could logically delay. This avoids too
635 // excessive buffering.
636 // We also wait if we sent eos, but didn't receive it yet (think of decoding
637 // stream with a very low number of frames).
638 if (ctx->frames_output || ctx->packets_sent > MAX_DELAYED_FRAMES || ctx->eos_sent) {
639 buffer = mmal_queue_wait(ctx->queue_decoded_frames);
640 } else {
641 buffer = mmal_queue_get(ctx->queue_decoded_frames);
642 }
643 if (!buffer)
644 goto done;
645
646 ctx->eos_received |= !!(buffer->flags & MMAL_BUFFER_HEADER_FLAG_EOS);
647 if (ctx->eos_received)
648 goto done;
649
650 if (buffer->cmd == MMAL_EVENT_FORMAT_CHANGED) {
651 MMAL_COMPONENT_T *decoder = ctx->decoder;
652 MMAL_EVENT_FORMAT_CHANGED_T *ev = mmal_event_format_changed_get(buffer);
653 MMAL_BUFFER_HEADER_T *stale_buffer;
654
655 av_log(avctx, AV_LOG_INFO, "Changing output format.\n");
656
657 if ((status = mmal_port_disable(decoder->output[0])))
658 goto done;
659
660 while ((stale_buffer = mmal_queue_get(ctx->queue_decoded_frames)))
661 mmal_buffer_header_release(stale_buffer);
662
663 mmal_format_copy(decoder->output[0]->format, ev->format);
664
665 if ((ret = ffmal_update_format(avctx)) < 0)
666 goto done;
667
668 if ((status = mmal_port_enable(decoder->output[0], output_callback)))
669 goto done;
670
671 if ((ret = ffmmal_fill_output_port(avctx)) < 0)
672 goto done;
673
674 if ((ret = ffmmal_fill_input_port(avctx)) < 0)
675 goto done;
676
677 mmal_buffer_header_release(buffer);
678 continue;
679 } else if (buffer->cmd) {
680 char s[20];
681 av_get_codec_tag_string(s, sizeof(s), buffer->cmd);
682 av_log(avctx, AV_LOG_WARNING, "Unknown MMAL event %s on output port\n", s);
683 goto done;
684 } else if (buffer->length == 0) {
685 // Unused output buffer that got drained after format change.
686 mmal_buffer_header_release(buffer);
687 continue;
688 }
689
690 ctx->frames_output++;
691
692 if ((ret = ffmal_copy_frame(avctx, frame, buffer)) < 0)
693 goto done;
694
695 *got_frame = 1;
696 break;
697 }
698
699 done:
700 if (buffer)
701 mmal_buffer_header_release(buffer);
702 if (status && ret >= 0)
703 ret = AVERROR_UNKNOWN;
704 return ret;
705 }
706
707 static int ffmmal_decode(AVCodecContext *avctx, void *data, int *got_frame,
708 AVPacket *avpkt)
709 {
710 AVFrame *frame = data;
711 int ret = 0;
712
713 if ((ret = ffmmal_add_packet(avctx, avpkt)) < 0)
714 return ret;
715
716 if ((ret = ffmmal_fill_input_port(avctx)) < 0)
717 return ret;
718
719 if ((ret = ffmmal_fill_output_port(avctx)) < 0)
720 return ret;
721
722 if ((ret = ffmmal_read_frame(avctx, frame, got_frame)) < 0)
723 return ret;
724
725 // ffmmal_read_frame() can block for a while. Since the decoder is
726 // asynchronous, it's a good idea to fill the ports again.
727
728 if ((ret = ffmmal_fill_output_port(avctx)) < 0)
729 return ret;
730
731 if ((ret = ffmmal_fill_input_port(avctx)) < 0)
732 return ret;
733
734 return ret;
735 }
736
737 AVHWAccel ff_h264_mmal_hwaccel = {
738 .name = "h264_mmal",
739 .type = AVMEDIA_TYPE_VIDEO,
740 .id = AV_CODEC_ID_H264,
741 .pix_fmt = AV_PIX_FMT_MMAL,
742 };
743
744 static const AVOption options[]={
745 {"extra_buffers", "extra buffers", offsetof(MMALDecodeContext, extra_buffers), AV_OPT_TYPE_INT, {.i64 = 10}, 0, 256, 0},
746 {NULL}
747 };
748
749 static const AVClass ffmmaldec_class = {
750 .class_name = "mmaldec",
751 .option = options,
752 .version = LIBAVUTIL_VERSION_INT,
753 };
754
755 AVCodec ff_h264_mmal_decoder = {
756 .name = "h264_mmal",
757 .long_name = NULL_IF_CONFIG_SMALL("h264 (mmal)"),
758 .type = AVMEDIA_TYPE_VIDEO,
759 .id = AV_CODEC_ID_H264,
760 .priv_data_size = sizeof(MMALDecodeContext),
761 .init = ffmmal_init_decoder,
762 .close = ffmmal_close_decoder,
763 .decode = ffmmal_decode,
764 .flush = ffmmal_flush,
765 .priv_class = &ffmmaldec_class,
766 .capabilities = CODEC_CAP_DELAY,
767 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MMAL,
768 AV_PIX_FMT_YUV420P,
769 AV_PIX_FMT_NONE},
770 };