avisynth: Simplify shared library name construction
[libav.git] / libavformat / avisynth.c
1 /*
2 * AviSynth/AvxSynth support
3 * Copyright (c) 2012 AvxSynth Team.
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 #include "libavutil/internal.h"
23 #include "libavcodec/internal.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "config.h"
27
28 /* Enable function pointer definitions for runtime loading. */
29 #define AVSC_NO_DECLSPEC
30
31 /* Platform-specific directives for AviSynth vs AvxSynth. */
32 #ifdef _WIN32
33 #include <windows.h>
34 #undef EXTERN_C
35 #include <avisynth/avisynth_c.h>
36 #define AVISYNTH_LIB "avisynth"
37 #define USING_AVISYNTH
38 #else
39 #include <dlfcn.h>
40 #include <avxsynth/avxsynth_c.h>
41 #define AVISYNTH_NAME "libavxsynth"
42 #define AVISYNTH_LIB AVISYNTH_NAME SLIBSUF
43
44 #define LoadLibrary(x) dlopen(x, RTLD_NOW | RTLD_LOCAL)
45 #define GetProcAddress dlsym
46 #define FreeLibrary dlclose
47 #endif
48
49 typedef struct AviSynthLibrary {
50 void *library;
51 #define AVSC_DECLARE_FUNC(name) name ## _func name
52 AVSC_DECLARE_FUNC(avs_bit_blt);
53 AVSC_DECLARE_FUNC(avs_clip_get_error);
54 AVSC_DECLARE_FUNC(avs_create_script_environment);
55 AVSC_DECLARE_FUNC(avs_delete_script_environment);
56 AVSC_DECLARE_FUNC(avs_get_audio);
57 AVSC_DECLARE_FUNC(avs_get_error);
58 AVSC_DECLARE_FUNC(avs_get_frame);
59 AVSC_DECLARE_FUNC(avs_get_version);
60 AVSC_DECLARE_FUNC(avs_get_video_info);
61 AVSC_DECLARE_FUNC(avs_invoke);
62 AVSC_DECLARE_FUNC(avs_release_clip);
63 AVSC_DECLARE_FUNC(avs_release_value);
64 AVSC_DECLARE_FUNC(avs_release_video_frame);
65 AVSC_DECLARE_FUNC(avs_take_clip);
66 #ifdef USING_AVISYNTH
67 AVSC_DECLARE_FUNC(avs_bits_per_pixel);
68 AVSC_DECLARE_FUNC(avs_get_height_p);
69 AVSC_DECLARE_FUNC(avs_get_pitch_p);
70 AVSC_DECLARE_FUNC(avs_get_read_ptr_p);
71 AVSC_DECLARE_FUNC(avs_get_row_size_p);
72 AVSC_DECLARE_FUNC(avs_is_yv24);
73 AVSC_DECLARE_FUNC(avs_is_yv16);
74 AVSC_DECLARE_FUNC(avs_is_yv411);
75 AVSC_DECLARE_FUNC(avs_is_y8);
76 #endif
77 #undef AVSC_DECLARE_FUNC
78 } AviSynthLibrary;
79
80 typedef struct AviSynthContext {
81 AVS_ScriptEnvironment *env;
82 AVS_Clip *clip;
83 const AVS_VideoInfo *vi;
84
85 /* avisynth_read_packet_video() iterates over this. */
86 int n_planes;
87 const int *planes;
88
89 int curr_stream;
90 int curr_frame;
91 int64_t curr_sample;
92
93 int error;
94
95 /* Linked list pointers. */
96 struct AviSynthContext *next;
97 } AviSynthContext;
98
99 static const int avs_planes_packed[1] = { 0 };
100 static const int avs_planes_grey[1] = { AVS_PLANAR_Y };
101 static const int avs_planes_yuv[3] = { AVS_PLANAR_Y, AVS_PLANAR_U,
102 AVS_PLANAR_V };
103
104 /* A conflict between C++ global objects, atexit, and dynamic loading requires
105 * us to register our own atexit handler to prevent double freeing. */
106 static AviSynthLibrary avs_library;
107 static int avs_atexit_called = 0;
108
109 /* Linked list of AviSynthContexts. An atexit handler destroys this list. */
110 static AviSynthContext *avs_ctx_list = NULL;
111
112 static av_cold void avisynth_atexit_handler(void);
113
114 static av_cold int avisynth_load_library(void)
115 {
116 avs_library.library = LoadLibrary(AVISYNTH_LIB);
117 if (!avs_library.library)
118 return AVERROR_UNKNOWN;
119
120 #define LOAD_AVS_FUNC(name, continue_on_fail) \
121 avs_library.name = \
122 (void *)GetProcAddress(avs_library.library, #name); \
123 if (!continue_on_fail && !avs_library.name) \
124 goto fail;
125
126 LOAD_AVS_FUNC(avs_bit_blt, 0);
127 LOAD_AVS_FUNC(avs_clip_get_error, 0);
128 LOAD_AVS_FUNC(avs_create_script_environment, 0);
129 LOAD_AVS_FUNC(avs_delete_script_environment, 0);
130 LOAD_AVS_FUNC(avs_get_audio, 0);
131 LOAD_AVS_FUNC(avs_get_error, 1); // New to AviSynth 2.6
132 LOAD_AVS_FUNC(avs_get_frame, 0);
133 LOAD_AVS_FUNC(avs_get_version, 0);
134 LOAD_AVS_FUNC(avs_get_video_info, 0);
135 LOAD_AVS_FUNC(avs_invoke, 0);
136 LOAD_AVS_FUNC(avs_release_clip, 0);
137 LOAD_AVS_FUNC(avs_release_value, 0);
138 LOAD_AVS_FUNC(avs_release_video_frame, 0);
139 LOAD_AVS_FUNC(avs_take_clip, 0);
140 #ifdef USING_AVISYNTH
141 LOAD_AVS_FUNC(avs_bits_per_pixel, 1);
142 LOAD_AVS_FUNC(avs_get_height_p, 1);
143 LOAD_AVS_FUNC(avs_get_pitch_p, 1);
144 LOAD_AVS_FUNC(avs_get_read_ptr_p, 1);
145 LOAD_AVS_FUNC(avs_get_row_size_p, 1);
146 LOAD_AVS_FUNC(avs_is_yv24, 1);
147 LOAD_AVS_FUNC(avs_is_yv16, 1);
148 LOAD_AVS_FUNC(avs_is_yv411, 1);
149 LOAD_AVS_FUNC(avs_is_y8, 1);
150 #endif
151 #undef LOAD_AVS_FUNC
152
153 atexit(avisynth_atexit_handler);
154 return 0;
155
156 fail:
157 FreeLibrary(avs_library.library);
158 return AVERROR_UNKNOWN;
159 }
160
161 /* Note that avisynth_context_create and avisynth_context_destroy
162 * do not allocate or free the actual context! That is taken care of
163 * by libavformat. */
164 static av_cold int avisynth_context_create(AVFormatContext *s)
165 {
166 AviSynthContext *avs = s->priv_data;
167 int ret;
168
169 if (!avs_library.library)
170 if (ret = avisynth_load_library())
171 return ret;
172
173 avs->env = avs_library.avs_create_script_environment(3);
174 if (avs_library.avs_get_error) {
175 const char *error = avs_library.avs_get_error(avs->env);
176 if (error) {
177 av_log(s, AV_LOG_ERROR, "%s\n", error);
178 return AVERROR_UNKNOWN;
179 }
180 }
181
182 if (!avs_ctx_list) {
183 avs_ctx_list = avs;
184 } else {
185 avs->next = avs_ctx_list;
186 avs_ctx_list = avs;
187 }
188
189 return 0;
190 }
191
192 static av_cold void avisynth_context_destroy(AviSynthContext *avs)
193 {
194 if (avs_atexit_called)
195 return;
196
197 if (avs == avs_ctx_list) {
198 avs_ctx_list = avs->next;
199 } else {
200 AviSynthContext *prev = avs_ctx_list;
201 while (prev->next != avs)
202 prev = prev->next;
203 prev->next = avs->next;
204 }
205
206 if (avs->clip) {
207 avs_library.avs_release_clip(avs->clip);
208 avs->clip = NULL;
209 }
210 if (avs->env) {
211 avs_library.avs_delete_script_environment(avs->env);
212 avs->env = NULL;
213 }
214 }
215
216 static av_cold void avisynth_atexit_handler(void)
217 {
218 AviSynthContext *avs = avs_ctx_list;
219
220 while (avs) {
221 AviSynthContext *next = avs->next;
222 avisynth_context_destroy(avs);
223 avs = next;
224 }
225 FreeLibrary(avs_library.library);
226
227 avs_atexit_called = 1;
228 }
229
230 /* Create AVStream from audio and video data. */
231 static int avisynth_create_stream_video(AVFormatContext *s, AVStream *st)
232 {
233 AviSynthContext *avs = s->priv_data;
234 int planar = 0; // 0: packed, 1: YUV, 2: Y8
235
236 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
237 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
238 st->codec->width = avs->vi->width;
239 st->codec->height = avs->vi->height;
240
241 st->time_base = (AVRational) { avs->vi->fps_denominator,
242 avs->vi->fps_numerator };
243 st->avg_frame_rate = (AVRational) { avs->vi->fps_numerator,
244 avs->vi->fps_denominator };
245 st->start_time = 0;
246 st->duration = avs->vi->num_frames;
247 st->nb_frames = avs->vi->num_frames;
248
249 switch (avs->vi->pixel_type) {
250 #ifdef USING_AVISYNTH
251 case AVS_CS_YV24:
252 st->codec->pix_fmt = AV_PIX_FMT_YUV444P;
253 planar = 1;
254 break;
255 case AVS_CS_YV16:
256 st->codec->pix_fmt = AV_PIX_FMT_YUV422P;
257 planar = 1;
258 break;
259 case AVS_CS_YV411:
260 st->codec->pix_fmt = AV_PIX_FMT_YUV411P;
261 planar = 1;
262 break;
263 case AVS_CS_Y8:
264 st->codec->pix_fmt = AV_PIX_FMT_GRAY8;
265 planar = 2;
266 break;
267 #endif
268 case AVS_CS_BGR24:
269 st->codec->pix_fmt = AV_PIX_FMT_BGR24;
270 break;
271 case AVS_CS_BGR32:
272 st->codec->pix_fmt = AV_PIX_FMT_RGB32;
273 break;
274 case AVS_CS_YUY2:
275 st->codec->pix_fmt = AV_PIX_FMT_YUYV422;
276 break;
277 case AVS_CS_YV12:
278 st->codec->pix_fmt = AV_PIX_FMT_YUV420P;
279 planar = 1;
280 break;
281 case AVS_CS_I420: // Is this even used anywhere?
282 st->codec->pix_fmt = AV_PIX_FMT_YUV420P;
283 planar = 1;
284 break;
285 default:
286 av_log(s, AV_LOG_ERROR,
287 "unknown AviSynth colorspace %d\n", avs->vi->pixel_type);
288 avs->error = 1;
289 return AVERROR_UNKNOWN;
290 }
291
292 switch (planar) {
293 case 2: // Y8
294 avs->n_planes = 1;
295 avs->planes = avs_planes_grey;
296 break;
297 case 1: // YUV
298 avs->n_planes = 3;
299 avs->planes = avs_planes_yuv;
300 break;
301 default:
302 avs->n_planes = 1;
303 avs->planes = avs_planes_packed;
304 }
305 return 0;
306 }
307
308 static int avisynth_create_stream_audio(AVFormatContext *s, AVStream *st)
309 {
310 AviSynthContext *avs = s->priv_data;
311
312 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
313 st->codec->sample_rate = avs->vi->audio_samples_per_second;
314 st->codec->channels = avs->vi->nchannels;
315 st->time_base = (AVRational) { 1,
316 avs->vi->audio_samples_per_second };
317 st->duration = avs->vi->num_audio_samples;
318
319 switch (avs->vi->sample_type) {
320 case AVS_SAMPLE_INT8:
321 st->codec->codec_id = AV_CODEC_ID_PCM_U8;
322 break;
323 case AVS_SAMPLE_INT16:
324 st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
325 break;
326 case AVS_SAMPLE_INT24:
327 st->codec->codec_id = AV_CODEC_ID_PCM_S24LE;
328 break;
329 case AVS_SAMPLE_INT32:
330 st->codec->codec_id = AV_CODEC_ID_PCM_S32LE;
331 break;
332 case AVS_SAMPLE_FLOAT:
333 st->codec->codec_id = AV_CODEC_ID_PCM_F32LE;
334 break;
335 default:
336 av_log(s, AV_LOG_ERROR,
337 "unknown AviSynth sample type %d\n", avs->vi->sample_type);
338 avs->error = 1;
339 return AVERROR_UNKNOWN;
340 }
341 return 0;
342 }
343
344 static int avisynth_create_stream(AVFormatContext *s)
345 {
346 AviSynthContext *avs = s->priv_data;
347 AVStream *st;
348 int ret;
349 int id = 0;
350
351 if (avs_has_video(avs->vi)) {
352 st = avformat_new_stream(s, NULL);
353 if (!st)
354 return AVERROR_UNKNOWN;
355 st->id = id++;
356 if (ret = avisynth_create_stream_video(s, st))
357 return ret;
358 }
359 if (avs_has_audio(avs->vi)) {
360 st = avformat_new_stream(s, NULL);
361 if (!st)
362 return AVERROR_UNKNOWN;
363 st->id = id++;
364 if (ret = avisynth_create_stream_audio(s, st))
365 return ret;
366 }
367 return 0;
368 }
369
370 static int avisynth_open_file(AVFormatContext *s)
371 {
372 AviSynthContext *avs = s->priv_data;
373 AVS_Value arg, val;
374 int ret;
375 #ifdef USING_AVISYNTH
376 char filename_ansi[MAX_PATH * 4];
377 wchar_t filename_wc[MAX_PATH * 4];
378 #endif
379
380 if (ret = avisynth_context_create(s))
381 return ret;
382
383 #ifdef USING_AVISYNTH
384 /* Convert UTF-8 to ANSI code page */
385 MultiByteToWideChar(CP_UTF8, 0, s->filename, -1, filename_wc, MAX_PATH * 4);
386 WideCharToMultiByte(CP_THREAD_ACP, 0, filename_wc, -1, filename_ansi,
387 MAX_PATH * 4, NULL, NULL);
388 arg = avs_new_value_string(filename_ansi);
389 #else
390 arg = avs_new_value_string(s->filename);
391 #endif
392 val = avs_library.avs_invoke(avs->env, "Import", arg, 0);
393 if (avs_is_error(val)) {
394 av_log(s, AV_LOG_ERROR, "%s\n", avs_as_error(val));
395 ret = AVERROR_UNKNOWN;
396 goto fail;
397 }
398 if (!avs_is_clip(val)) {
399 av_log(s, AV_LOG_ERROR, "AviSynth script did not return a clip\n");
400 ret = AVERROR_UNKNOWN;
401 goto fail;
402 }
403
404 avs->clip = avs_library.avs_take_clip(val, avs->env);
405 avs->vi = avs_library.avs_get_video_info(avs->clip);
406
407 #ifdef USING_AVISYNTH
408 /* On Windows, libav supports AviSynth interface version 6 or higher.
409 * This includes AviSynth 2.6 RC1 or higher, and AviSynth+ r1718 or higher,
410 * and excludes 2.5 and the 2.6 alphas. Since AvxSynth identifies itself
411 * as interface version 3 like 2.5.8, this needs to be special-cased. */
412
413 if (avs_library.avs_get_version(avs->clip) < 6) {
414 av_log(s, AV_LOG_ERROR,
415 "AviSynth version is too old. Please upgrade to either AviSynth 2.6 >= RC1 or AviSynth+ >= r1718.\n");
416 ret = AVERROR_UNKNOWN;
417 goto fail;
418 }
419 #endif
420
421 /* Release the AVS_Value as it will go out of scope. */
422 avs_library.avs_release_value(val);
423
424 if (ret = avisynth_create_stream(s))
425 goto fail;
426
427 return 0;
428
429 fail:
430 avisynth_context_destroy(avs);
431 return ret;
432 }
433
434 static void avisynth_next_stream(AVFormatContext *s, AVStream **st,
435 AVPacket *pkt, int *discard)
436 {
437 AviSynthContext *avs = s->priv_data;
438
439 avs->curr_stream++;
440 avs->curr_stream %= s->nb_streams;
441
442 *st = s->streams[avs->curr_stream];
443 if ((*st)->discard == AVDISCARD_ALL)
444 *discard = 1;
445 else
446 *discard = 0;
447
448 return;
449 }
450
451 /* Copy AviSynth clip data into an AVPacket. */
452 static int avisynth_read_packet_video(AVFormatContext *s, AVPacket *pkt,
453 int discard)
454 {
455 AviSynthContext *avs = s->priv_data;
456 AVS_VideoFrame *frame;
457 unsigned char *dst_p;
458 const unsigned char *src_p;
459 int n, i, plane, rowsize, planeheight, pitch, bits;
460 const char *error;
461
462 if (avs->curr_frame >= avs->vi->num_frames)
463 return AVERROR_EOF;
464
465 /* This must happen even if the stream is discarded to prevent desync. */
466 n = avs->curr_frame++;
467 if (discard)
468 return 0;
469
470 #ifdef USING_AVISYNTH
471 /* Define the bpp values for the new AviSynth 2.6 colorspaces.
472 * Since AvxSynth doesn't have these functions, special-case
473 * it in order to avoid implicit declaration errors. */
474
475 if (avs_library.avs_is_yv24(avs->vi))
476 bits = 24;
477 else if (avs_library.avs_is_yv16(avs->vi))
478 bits = 16;
479 else if (avs_library.avs_is_yv411(avs->vi))
480 bits = 12;
481 else if (avs_library.avs_is_y8(avs->vi))
482 bits = 8;
483 else
484 bits = avs_library.avs_bits_per_pixel(avs->vi);
485 #else
486 bits = avs_bits_per_pixel(avs->vi);
487 #endif
488
489 /* Without the cast to int64_t, calculation overflows at about 9k x 9k
490 * resolution. */
491 pkt->size = (((int64_t)avs->vi->width *
492 (int64_t)avs->vi->height) * bits) / 8;
493 if (!pkt->size)
494 return AVERROR_UNKNOWN;
495
496 if (av_new_packet(pkt, pkt->size) < 0)
497 return AVERROR(ENOMEM);
498
499 pkt->pts = n;
500 pkt->dts = n;
501 pkt->duration = 1;
502 pkt->stream_index = avs->curr_stream;
503
504 frame = avs_library.avs_get_frame(avs->clip, n);
505 error = avs_library.avs_clip_get_error(avs->clip);
506 if (error) {
507 av_log(s, AV_LOG_ERROR, "%s\n", error);
508 avs->error = 1;
509 av_packet_unref(pkt);
510 return AVERROR_UNKNOWN;
511 }
512
513 dst_p = pkt->data;
514 for (i = 0; i < avs->n_planes; i++) {
515 plane = avs->planes[i];
516 #ifdef USING_AVISYNTH
517 src_p = avs_library.avs_get_read_ptr_p(frame, plane);
518 pitch = avs_library.avs_get_pitch_p(frame, plane);
519
520 rowsize = avs_library.avs_get_row_size_p(frame, plane);
521 planeheight = avs_library.avs_get_height_p(frame, plane);
522 #else
523 src_p = avs_get_read_ptr_p(frame, plane);
524 pitch = avs_get_pitch_p(frame, plane);
525
526 rowsize = avs_get_row_size_p(frame, plane);
527 planeheight = avs_get_height_p(frame, plane);
528 #endif
529
530 /* Flip RGB video. */
531 if (avs_is_rgb24(avs->vi) || avs_is_rgb(avs->vi)) {
532 src_p = src_p + (planeheight - 1) * pitch;
533 pitch = -pitch;
534 }
535
536 avs_library.avs_bit_blt(avs->env, dst_p, rowsize, src_p, pitch,
537 rowsize, planeheight);
538 dst_p += rowsize * planeheight;
539 }
540
541 avs_library.avs_release_video_frame(frame);
542 return 0;
543 }
544
545 static int avisynth_read_packet_audio(AVFormatContext *s, AVPacket *pkt,
546 int discard)
547 {
548 AviSynthContext *avs = s->priv_data;
549 AVRational fps, samplerate;
550 int samples;
551 int64_t n;
552 const char *error;
553
554 if (avs->curr_sample >= avs->vi->num_audio_samples)
555 return AVERROR_EOF;
556
557 fps.num = avs->vi->fps_numerator;
558 fps.den = avs->vi->fps_denominator;
559 samplerate.num = avs->vi->audio_samples_per_second;
560 samplerate.den = 1;
561
562 if (avs_has_video(avs->vi)) {
563 if (avs->curr_frame < avs->vi->num_frames)
564 samples = av_rescale_q(avs->curr_frame, samplerate, fps) -
565 avs->curr_sample;
566 else
567 samples = av_rescale_q(1, samplerate, fps);
568 } else {
569 samples = 1000;
570 }
571
572 /* After seeking, audio may catch up with video. */
573 if (samples <= 0) {
574 pkt->size = 0;
575 pkt->data = NULL;
576 return 0;
577 }
578
579 if (avs->curr_sample + samples > avs->vi->num_audio_samples)
580 samples = avs->vi->num_audio_samples - avs->curr_sample;
581
582 /* This must happen even if the stream is discarded to prevent desync. */
583 n = avs->curr_sample;
584 avs->curr_sample += samples;
585 if (discard)
586 return 0;
587
588 pkt->size = avs_bytes_per_channel_sample(avs->vi) *
589 samples * avs->vi->nchannels;
590 if (!pkt->size)
591 return AVERROR_UNKNOWN;
592
593 if (av_new_packet(pkt, pkt->size) < 0)
594 return AVERROR(ENOMEM);
595
596 pkt->pts = n;
597 pkt->dts = n;
598 pkt->duration = samples;
599 pkt->stream_index = avs->curr_stream;
600
601 avs_library.avs_get_audio(avs->clip, pkt->data, n, samples);
602 error = avs_library.avs_clip_get_error(avs->clip);
603 if (error) {
604 av_log(s, AV_LOG_ERROR, "%s\n", error);
605 avs->error = 1;
606 av_packet_unref(pkt);
607 return AVERROR_UNKNOWN;
608 }
609 return 0;
610 }
611
612 static av_cold int avisynth_read_header(AVFormatContext *s)
613 {
614 int ret;
615
616 // Calling library must implement a lock for thread-safe opens.
617 if (ret = avpriv_lock_avformat())
618 return ret;
619
620 if (ret = avisynth_open_file(s)) {
621 avpriv_unlock_avformat();
622 return ret;
623 }
624
625 avpriv_unlock_avformat();
626 return 0;
627 }
628
629 static int avisynth_read_packet(AVFormatContext *s, AVPacket *pkt)
630 {
631 AviSynthContext *avs = s->priv_data;
632 AVStream *st;
633 int discard = 0;
634 int ret;
635
636 if (avs->error)
637 return AVERROR_UNKNOWN;
638
639 /* If either stream reaches EOF, try to read the other one before
640 * giving up. */
641 avisynth_next_stream(s, &st, pkt, &discard);
642 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
643 ret = avisynth_read_packet_video(s, pkt, discard);
644 if (ret == AVERROR_EOF && avs_has_audio(avs->vi)) {
645 avisynth_next_stream(s, &st, pkt, &discard);
646 return avisynth_read_packet_audio(s, pkt, discard);
647 }
648 } else {
649 ret = avisynth_read_packet_audio(s, pkt, discard);
650 if (ret == AVERROR_EOF && avs_has_video(avs->vi)) {
651 avisynth_next_stream(s, &st, pkt, &discard);
652 return avisynth_read_packet_video(s, pkt, discard);
653 }
654 }
655
656 return ret;
657 }
658
659 static av_cold int avisynth_read_close(AVFormatContext *s)
660 {
661 if (avpriv_lock_avformat())
662 return AVERROR_UNKNOWN;
663
664 avisynth_context_destroy(s->priv_data);
665 avpriv_unlock_avformat();
666 return 0;
667 }
668
669 static int avisynth_read_seek(AVFormatContext *s, int stream_index,
670 int64_t timestamp, int flags)
671 {
672 AviSynthContext *avs = s->priv_data;
673 AVStream *st;
674 AVRational fps, samplerate;
675
676 if (avs->error)
677 return AVERROR_UNKNOWN;
678
679 fps = (AVRational) { avs->vi->fps_numerator,
680 avs->vi->fps_denominator };
681 samplerate = (AVRational) { avs->vi->audio_samples_per_second, 1 };
682
683 st = s->streams[stream_index];
684 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
685 /* AviSynth frame counts are signed int. */
686 if ((timestamp >= avs->vi->num_frames) ||
687 (timestamp > INT_MAX) ||
688 (timestamp < 0))
689 return AVERROR_EOF;
690 avs->curr_frame = timestamp;
691 if (avs_has_audio(avs->vi))
692 avs->curr_sample = av_rescale_q(timestamp, samplerate, fps);
693 } else {
694 if ((timestamp >= avs->vi->num_audio_samples) || (timestamp < 0))
695 return AVERROR_EOF;
696 /* Force frame granularity for seeking. */
697 if (avs_has_video(avs->vi)) {
698 avs->curr_frame = av_rescale_q(timestamp, fps, samplerate);
699 avs->curr_sample = av_rescale_q(avs->curr_frame, samplerate, fps);
700 } else {
701 avs->curr_sample = timestamp;
702 }
703 }
704
705 return 0;
706 }
707
708 AVInputFormat ff_avisynth_demuxer = {
709 .name = "avisynth",
710 .long_name = NULL_IF_CONFIG_SMALL("AviSynth script"),
711 .priv_data_size = sizeof(AviSynthContext),
712 .read_header = avisynth_read_header,
713 .read_packet = avisynth_read_packet,
714 .read_close = avisynth_read_close,
715 .read_seek = avisynth_read_seek,
716 .extensions = "avs",
717 };