3 * Copyright (c) 2012 AvxSynth Team
5 * This file is part of FFmpeg
7 * FFmpeg 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.
12 * FFmpeg 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/attributes.h"
23 #include "libavutil/internal.h"
25 #include "libavcodec/internal.h"
31 /* Enable function pointer definitions for runtime loading. */
32 #define AVSC_NO_DECLSPEC
34 /* Platform-specific directives. */
36 #include "compat/w32dlfcn.h"
38 #define AVISYNTH_LIB "avisynth"
41 #define AVISYNTH_NAME "libavisynth"
42 #define AVISYNTH_LIB AVISYNTH_NAME SLIBSUF
45 /* Endianness guards for audio */
47 #define PCM(format) (AV_CODEC_ID_PCM_ ## format ## BE)
49 #define PCM(format) (AV_CODEC_ID_PCM_ ## format ## LE)
52 #include <avisynth/avisynth_c.h>
54 typedef struct AviSynthLibrary {
56 #define AVSC_DECLARE_FUNC(name) name ## _func name
57 AVSC_DECLARE_FUNC(avs_bit_blt);
58 AVSC_DECLARE_FUNC(avs_clip_get_error);
59 AVSC_DECLARE_FUNC(avs_create_script_environment);
60 AVSC_DECLARE_FUNC(avs_delete_script_environment);
61 AVSC_DECLARE_FUNC(avs_get_audio);
62 AVSC_DECLARE_FUNC(avs_get_error);
63 AVSC_DECLARE_FUNC(avs_get_frame);
64 AVSC_DECLARE_FUNC(avs_get_version);
65 AVSC_DECLARE_FUNC(avs_get_video_info);
66 AVSC_DECLARE_FUNC(avs_invoke);
67 AVSC_DECLARE_FUNC(avs_is_color_space);
68 AVSC_DECLARE_FUNC(avs_release_clip);
69 AVSC_DECLARE_FUNC(avs_release_value);
70 AVSC_DECLARE_FUNC(avs_release_video_frame);
71 AVSC_DECLARE_FUNC(avs_take_clip);
72 AVSC_DECLARE_FUNC(avs_bits_per_pixel);
73 AVSC_DECLARE_FUNC(avs_get_height_p);
74 AVSC_DECLARE_FUNC(avs_get_pitch_p);
75 AVSC_DECLARE_FUNC(avs_get_read_ptr_p);
76 AVSC_DECLARE_FUNC(avs_get_row_size_p);
77 AVSC_DECLARE_FUNC(avs_is_planar_rgb);
78 AVSC_DECLARE_FUNC(avs_is_planar_rgba);
79 #undef AVSC_DECLARE_FUNC
82 typedef struct AviSynthContext {
83 AVS_ScriptEnvironment *env;
85 const AVS_VideoInfo *vi;
87 /* avisynth_read_packet_video() iterates over this. */
97 /* Linked list pointers. */
98 struct AviSynthContext *next;
101 static const int avs_planes_packed[1] = { 0 };
102 static const int avs_planes_grey[1] = { AVS_PLANAR_Y };
103 static const int avs_planes_yuv[3] = { AVS_PLANAR_Y, AVS_PLANAR_U,
105 static const int avs_planes_rgb[3] = { AVS_PLANAR_G, AVS_PLANAR_B,
107 static const int avs_planes_yuva[4] = { AVS_PLANAR_Y, AVS_PLANAR_U,
108 AVS_PLANAR_V, AVS_PLANAR_A };
109 static const int avs_planes_rgba[4] = { AVS_PLANAR_G, AVS_PLANAR_B,
110 AVS_PLANAR_R, AVS_PLANAR_A };
112 /* A conflict between C++ global objects, atexit, and dynamic loading requires
113 * us to register our own atexit handler to prevent double freeing. */
114 static AviSynthLibrary avs_library;
115 static int avs_atexit_called = 0;
117 /* Linked list of AviSynthContexts. An atexit handler destroys this list. */
118 static AviSynthContext *avs_ctx_list = NULL;
120 static av_cold void avisynth_atexit_handler(void);
122 static av_cold int avisynth_load_library(void)
124 avs_library.library = dlopen(AVISYNTH_LIB, RTLD_NOW | RTLD_LOCAL);
125 if (!avs_library.library)
126 return AVERROR_UNKNOWN;
128 #define LOAD_AVS_FUNC(name, continue_on_fail) \
129 avs_library.name = (name ## _func) \
130 dlsym(avs_library.library, #name); \
131 if (!continue_on_fail && !avs_library.name) \
134 LOAD_AVS_FUNC(avs_bit_blt, 0);
135 LOAD_AVS_FUNC(avs_clip_get_error, 0);
136 LOAD_AVS_FUNC(avs_create_script_environment, 0);
137 LOAD_AVS_FUNC(avs_delete_script_environment, 0);
138 LOAD_AVS_FUNC(avs_get_audio, 0);
139 LOAD_AVS_FUNC(avs_get_error, 1); // New to AviSynth 2.6
140 LOAD_AVS_FUNC(avs_get_frame, 0);
141 LOAD_AVS_FUNC(avs_get_version, 0);
142 LOAD_AVS_FUNC(avs_get_video_info, 0);
143 LOAD_AVS_FUNC(avs_invoke, 0);
144 LOAD_AVS_FUNC(avs_is_color_space, 1);
145 LOAD_AVS_FUNC(avs_release_clip, 0);
146 LOAD_AVS_FUNC(avs_release_value, 0);
147 LOAD_AVS_FUNC(avs_release_video_frame, 0);
148 LOAD_AVS_FUNC(avs_take_clip, 0);
149 LOAD_AVS_FUNC(avs_bits_per_pixel, 1);
150 LOAD_AVS_FUNC(avs_get_height_p, 1);
151 LOAD_AVS_FUNC(avs_get_pitch_p, 1);
152 LOAD_AVS_FUNC(avs_get_read_ptr_p, 1);
153 LOAD_AVS_FUNC(avs_get_row_size_p, 1);
154 LOAD_AVS_FUNC(avs_is_planar_rgb, 1);
155 LOAD_AVS_FUNC(avs_is_planar_rgba, 1);
158 atexit(avisynth_atexit_handler);
162 dlclose(avs_library.library);
163 return AVERROR_UNKNOWN;
166 /* Note that avisynth_context_create and avisynth_context_destroy
167 * do not allocate or free the actual context! That is taken care of
169 static av_cold int avisynth_context_create(AVFormatContext *s)
171 AviSynthContext *avs = s->priv_data;
174 if (!avs_library.library)
175 if (ret = avisynth_load_library())
178 avs->env = avs_library.avs_create_script_environment(3);
179 if (avs_library.avs_get_error) {
180 const char *error = avs_library.avs_get_error(avs->env);
182 av_log(s, AV_LOG_ERROR, "%s\n", error);
183 return AVERROR_UNKNOWN;
190 avs->next = avs_ctx_list;
197 static av_cold void avisynth_context_destroy(AviSynthContext *avs)
199 if (avs_atexit_called)
202 if (avs == avs_ctx_list) {
203 avs_ctx_list = avs->next;
205 AviSynthContext *prev = avs_ctx_list;
206 while (prev->next != avs)
208 prev->next = avs->next;
212 avs_library.avs_release_clip(avs->clip);
216 avs_library.avs_delete_script_environment(avs->env);
221 static av_cold void avisynth_atexit_handler(void)
223 AviSynthContext *avs = avs_ctx_list;
226 AviSynthContext *next = avs->next;
227 avisynth_context_destroy(avs);
230 dlclose(avs_library.library);
232 avs_atexit_called = 1;
235 /* Create AVStream from audio and video data. */
236 static int avisynth_create_stream_video(AVFormatContext *s, AVStream *st)
238 AviSynthContext *avs = s->priv_data;
239 int planar = 0; // 0: packed, 1: YUV, 2: Y8, 3: Planar RGB, 4: YUVA, 5: Planar RGBA
241 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
242 st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
243 st->codecpar->width = avs->vi->width;
244 st->codecpar->height = avs->vi->height;
246 st->avg_frame_rate = (AVRational) { avs->vi->fps_numerator,
247 avs->vi->fps_denominator };
249 st->duration = avs->vi->num_frames;
250 st->nb_frames = avs->vi->num_frames;
251 avpriv_set_pts_info(st, 32, avs->vi->fps_denominator, avs->vi->fps_numerator);
253 av_log(s, AV_LOG_TRACE, "avs_is_field_based: %d\n", avs_is_field_based(avs->vi));
254 av_log(s, AV_LOG_TRACE, "avs_is_parity_known: %d\n", avs_is_parity_known(avs->vi));
256 /* The following typically only works when assumetff (-bff) and
257 * assumefieldbased is used in-script. Additional
258 * logic using GetParity() could deliver more accurate results
259 * but also decodes a frame which we want to avoid. */
260 st->codecpar->field_order = AV_FIELD_UNKNOWN;
261 if (avs_is_field_based(avs->vi)) {
262 if (avs_is_tff(avs->vi)) {
263 st->codecpar->field_order = AV_FIELD_TT;
265 else if (avs_is_bff(avs->vi)) {
266 st->codecpar->field_order = AV_FIELD_BB;
270 switch (avs->vi->pixel_type) {
271 /* 10~16-bit YUV pix_fmts (AviSynth+) */
272 case AVS_CS_YUV444P10:
273 st->codecpar->format = AV_PIX_FMT_YUV444P10;
276 case AVS_CS_YUV422P10:
277 st->codecpar->format = AV_PIX_FMT_YUV422P10;
280 case AVS_CS_YUV420P10:
281 st->codecpar->format = AV_PIX_FMT_YUV420P10;
284 case AVS_CS_YUV444P12:
285 st->codecpar->format = AV_PIX_FMT_YUV444P12;
288 case AVS_CS_YUV422P12:
289 st->codecpar->format = AV_PIX_FMT_YUV422P12;
292 case AVS_CS_YUV420P12:
293 st->codecpar->format = AV_PIX_FMT_YUV420P12;
296 case AVS_CS_YUV444P14:
297 st->codecpar->format = AV_PIX_FMT_YUV444P14;
300 case AVS_CS_YUV422P14:
301 st->codecpar->format = AV_PIX_FMT_YUV422P14;
304 case AVS_CS_YUV420P14:
305 st->codecpar->format = AV_PIX_FMT_YUV420P14;
308 case AVS_CS_YUV444P16:
309 st->codecpar->format = AV_PIX_FMT_YUV444P16;
312 case AVS_CS_YUV422P16:
313 st->codecpar->format = AV_PIX_FMT_YUV422P16;
316 case AVS_CS_YUV420P16:
317 st->codecpar->format = AV_PIX_FMT_YUV420P16;
320 /* 8~16-bit YUV pix_fmts with Alpha (AviSynth+) */
322 st->codecpar->format = AV_PIX_FMT_YUVA444P;
326 st->codecpar->format = AV_PIX_FMT_YUVA422P;
330 st->codecpar->format = AV_PIX_FMT_YUVA420P;
333 case AVS_CS_YUVA444P10:
334 st->codecpar->format = AV_PIX_FMT_YUVA444P10;
337 case AVS_CS_YUVA422P10:
338 st->codecpar->format = AV_PIX_FMT_YUVA422P10;
341 case AVS_CS_YUVA420P10:
342 st->codecpar->format = AV_PIX_FMT_YUVA420P10;
345 case AVS_CS_YUVA422P12:
346 st->codecpar->format = AV_PIX_FMT_YUVA422P12;
349 case AVS_CS_YUVA444P16:
350 st->codecpar->format = AV_PIX_FMT_YUVA444P16;
353 case AVS_CS_YUVA422P16:
354 st->codecpar->format = AV_PIX_FMT_YUVA422P16;
357 case AVS_CS_YUVA420P16:
358 st->codecpar->format = AV_PIX_FMT_YUVA420P16;
361 /* Planar RGB pix_fmts (AviSynth+) */
363 st->codecpar->format = AV_PIX_FMT_GBRP;
367 st->codecpar->format = AV_PIX_FMT_GBRP10;
371 st->codecpar->format = AV_PIX_FMT_GBRP12;
375 st->codecpar->format = AV_PIX_FMT_GBRP14;
379 st->codecpar->format = AV_PIX_FMT_GBRP16;
382 /* Single precision floating point Planar RGB (AviSynth+) */
384 st->codecpar->format = AV_PIX_FMT_GBRPF32;
387 /* Planar RGB pix_fmts with Alpha (AviSynth+) */
389 st->codecpar->format = AV_PIX_FMT_GBRAP;
393 st->codecpar->format = AV_PIX_FMT_GBRAP10;
397 st->codecpar->format = AV_PIX_FMT_GBRAP12;
401 st->codecpar->format = AV_PIX_FMT_GBRAP16;
404 /* Single precision floating point Planar RGB with Alpha (AviSynth+) */
406 st->codecpar->format = AV_PIX_FMT_GBRAPF32;
409 /* 10~16-bit gray pix_fmts (AviSynth+) */
411 st->codecpar->format = AV_PIX_FMT_GRAY10;
415 st->codecpar->format = AV_PIX_FMT_GRAY12;
419 st->codecpar->format = AV_PIX_FMT_GRAY14;
423 st->codecpar->format = AV_PIX_FMT_GRAY16;
426 /* Single precision floating point gray (AviSynth+) */
428 st->codecpar->format = AV_PIX_FMT_GRAYF32;
431 /* pix_fmts added in AviSynth 2.6 */
433 st->codecpar->format = AV_PIX_FMT_YUV444P;
437 st->codecpar->format = AV_PIX_FMT_YUV422P;
441 st->codecpar->format = AV_PIX_FMT_YUV411P;
445 st->codecpar->format = AV_PIX_FMT_GRAY8;
448 /* 16-bit packed RGB pix_fmts (AviSynth+) */
450 st->codecpar->format = AV_PIX_FMT_BGR48;
453 st->codecpar->format = AV_PIX_FMT_BGRA64;
455 /* AviSynth 2.5 pix_fmts */
457 st->codecpar->format = AV_PIX_FMT_BGR24;
460 st->codecpar->format = AV_PIX_FMT_RGB32;
463 st->codecpar->format = AV_PIX_FMT_YUYV422;
466 st->codecpar->format = AV_PIX_FMT_YUV420P;
469 case AVS_CS_I420: // Is this even used anywhere?
470 st->codecpar->format = AV_PIX_FMT_YUV420P;
474 av_log(s, AV_LOG_ERROR,
475 "unknown AviSynth colorspace %d\n", avs->vi->pixel_type);
477 return AVERROR_UNKNOWN;
481 case 5: // Planar RGB + Alpha
483 avs->planes = avs_planes_rgba;
485 case 4: // YUV + Alpha
487 avs->planes = avs_planes_yuva;
489 case 3: // Planar RGB
491 avs->planes = avs_planes_rgb;
495 avs->planes = avs_planes_grey;
499 avs->planes = avs_planes_yuv;
503 avs->planes = avs_planes_packed;
508 static int avisynth_create_stream_audio(AVFormatContext *s, AVStream *st)
510 AviSynthContext *avs = s->priv_data;
512 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
513 st->codecpar->sample_rate = avs->vi->audio_samples_per_second;
514 st->codecpar->channels = avs->vi->nchannels;
515 st->duration = avs->vi->num_audio_samples;
516 avpriv_set_pts_info(st, 64, 1, avs->vi->audio_samples_per_second);
518 switch (avs->vi->sample_type) {
519 case AVS_SAMPLE_INT8:
520 st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
522 case AVS_SAMPLE_INT16:
523 st->codecpar->codec_id = PCM(S16);
525 case AVS_SAMPLE_INT24:
526 st->codecpar->codec_id = PCM(S24);
528 case AVS_SAMPLE_INT32:
529 st->codecpar->codec_id = PCM(S32);
531 case AVS_SAMPLE_FLOAT:
532 st->codecpar->codec_id = PCM(F32);
535 av_log(s, AV_LOG_ERROR,
536 "unknown AviSynth sample type %d\n", avs->vi->sample_type);
538 return AVERROR_UNKNOWN;
543 static int avisynth_create_stream(AVFormatContext *s)
545 AviSynthContext *avs = s->priv_data;
550 if (avs_has_video(avs->vi)) {
551 st = avformat_new_stream(s, NULL);
553 return AVERROR_UNKNOWN;
555 if (ret = avisynth_create_stream_video(s, st))
558 if (avs_has_audio(avs->vi)) {
559 st = avformat_new_stream(s, NULL);
561 return AVERROR_UNKNOWN;
563 if (ret = avisynth_create_stream_audio(s, st))
569 static int avisynth_open_file(AVFormatContext *s)
571 AviSynthContext *avs = s->priv_data;
575 char filename_ansi[MAX_PATH * 4];
576 wchar_t filename_wc[MAX_PATH * 4];
579 if (ret = avisynth_context_create(s))
583 /* Convert UTF-8 to ANSI code page */
584 MultiByteToWideChar(CP_UTF8, 0, s->url, -1, filename_wc, MAX_PATH * 4);
585 WideCharToMultiByte(CP_THREAD_ACP, 0, filename_wc, -1, filename_ansi,
586 MAX_PATH * 4, NULL, NULL);
587 arg = avs_new_value_string(filename_ansi);
589 arg = avs_new_value_string(s->url);
591 val = avs_library.avs_invoke(avs->env, "Import", arg, 0);
592 if (avs_is_error(val)) {
593 av_log(s, AV_LOG_ERROR, "%s\n", avs_as_error(val));
594 ret = AVERROR_UNKNOWN;
597 if (!avs_is_clip(val)) {
598 av_log(s, AV_LOG_ERROR, "AviSynth script did not return a clip\n");
599 ret = AVERROR_UNKNOWN;
603 avs->clip = avs_library.avs_take_clip(val, avs->env);
604 avs->vi = avs_library.avs_get_video_info(avs->clip);
606 /* On Windows, FFmpeg supports AviSynth interface version 6 or higher.
607 * This includes AviSynth 2.6 RC1 or higher, and AviSynth+ r1718 or higher,
608 * and excludes 2.5 and the 2.6 alphas. */
610 if (avs_library.avs_get_version(avs->clip) < 6) {
611 av_log(s, AV_LOG_ERROR,
612 "AviSynth version is too old. Please upgrade to either AviSynth 2.6 >= RC1 or AviSynth+ >= r1718.\n");
613 ret = AVERROR_UNKNOWN;
617 /* Release the AVS_Value as it will go out of scope. */
618 avs_library.avs_release_value(val);
620 if (ret = avisynth_create_stream(s))
626 avisynth_context_destroy(avs);
630 static void avisynth_next_stream(AVFormatContext *s, AVStream **st,
631 AVPacket *pkt, int *discard)
633 AviSynthContext *avs = s->priv_data;
636 avs->curr_stream %= s->nb_streams;
638 *st = s->streams[avs->curr_stream];
639 if ((*st)->discard == AVDISCARD_ALL)
647 /* Copy AviSynth clip data into an AVPacket. */
648 static int avisynth_read_packet_video(AVFormatContext *s, AVPacket *pkt,
651 AviSynthContext *avs = s->priv_data;
652 AVS_VideoFrame *frame;
653 unsigned char *dst_p;
654 const unsigned char *src_p;
655 int n, i, plane, rowsize, planeheight, pitch, bits, ret;
658 if (avs->curr_frame >= avs->vi->num_frames)
661 /* This must happen even if the stream is discarded to prevent desync. */
662 n = avs->curr_frame++;
666 bits = avs_library.avs_bits_per_pixel(avs->vi);
668 /* Without the cast to int64_t, calculation overflows at about 9k x 9k
670 pkt->size = (((int64_t)avs->vi->width *
671 (int64_t)avs->vi->height) * bits) / 8;
673 return AVERROR_UNKNOWN;
675 if ((ret = av_new_packet(pkt, pkt->size)) < 0)
681 pkt->stream_index = avs->curr_stream;
683 frame = avs_library.avs_get_frame(avs->clip, n);
684 error = avs_library.avs_clip_get_error(avs->clip);
686 av_log(s, AV_LOG_ERROR, "%s\n", error);
688 av_packet_unref(pkt);
689 return AVERROR_UNKNOWN;
693 for (i = 0; i < avs->n_planes; i++) {
694 plane = avs->planes[i];
695 src_p = avs_library.avs_get_read_ptr_p(frame, plane);
696 pitch = avs_library.avs_get_pitch_p(frame, plane);
698 rowsize = avs_library.avs_get_row_size_p(frame, plane);
699 planeheight = avs_library.avs_get_height_p(frame, plane);
701 /* Flip RGB video. */
702 if (avs_library.avs_is_color_space(avs->vi, AVS_CS_BGR) ||
703 avs_library.avs_is_color_space(avs->vi, AVS_CS_BGR48) ||
704 avs_library.avs_is_color_space(avs->vi, AVS_CS_BGR64)) {
705 src_p = src_p + (planeheight - 1) * pitch;
709 avs_library.avs_bit_blt(avs->env, dst_p, rowsize, src_p, pitch,
710 rowsize, planeheight);
711 dst_p += rowsize * planeheight;
714 avs_library.avs_release_video_frame(frame);
718 static int avisynth_read_packet_audio(AVFormatContext *s, AVPacket *pkt,
721 AviSynthContext *avs = s->priv_data;
722 AVRational fps, samplerate;
727 if (avs->curr_sample >= avs->vi->num_audio_samples)
730 fps.num = avs->vi->fps_numerator;
731 fps.den = avs->vi->fps_denominator;
732 samplerate.num = avs->vi->audio_samples_per_second;
735 if (avs_has_video(avs->vi)) {
736 if (avs->curr_frame < avs->vi->num_frames)
737 samples = av_rescale_q(avs->curr_frame, samplerate, fps) -
740 samples = av_rescale_q(1, samplerate, fps);
745 /* After seeking, audio may catch up with video. */
752 if (avs->curr_sample + samples > avs->vi->num_audio_samples)
753 samples = avs->vi->num_audio_samples - avs->curr_sample;
755 /* This must happen even if the stream is discarded to prevent desync. */
756 n = avs->curr_sample;
757 avs->curr_sample += samples;
761 pkt->size = avs_bytes_per_channel_sample(avs->vi) *
762 samples * avs->vi->nchannels;
764 return AVERROR_UNKNOWN;
766 if ((ret = av_new_packet(pkt, pkt->size)) < 0)
771 pkt->duration = samples;
772 pkt->stream_index = avs->curr_stream;
774 avs_library.avs_get_audio(avs->clip, pkt->data, n, samples);
775 error = avs_library.avs_clip_get_error(avs->clip);
777 av_log(s, AV_LOG_ERROR, "%s\n", error);
779 av_packet_unref(pkt);
780 return AVERROR_UNKNOWN;
785 static av_cold int avisynth_read_header(AVFormatContext *s)
789 // Calling library must implement a lock for thread-safe opens.
790 if (ret = ff_lock_avformat())
793 if (ret = avisynth_open_file(s)) {
794 ff_unlock_avformat();
798 ff_unlock_avformat();
802 static int avisynth_read_packet(AVFormatContext *s, AVPacket *pkt)
804 AviSynthContext *avs = s->priv_data;
810 return AVERROR_UNKNOWN;
812 /* If either stream reaches EOF, try to read the other one before
814 avisynth_next_stream(s, &st, pkt, &discard);
815 if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
816 ret = avisynth_read_packet_video(s, pkt, discard);
817 if (ret == AVERROR_EOF && avs_has_audio(avs->vi)) {
818 avisynth_next_stream(s, &st, pkt, &discard);
819 return avisynth_read_packet_audio(s, pkt, discard);
822 ret = avisynth_read_packet_audio(s, pkt, discard);
823 if (ret == AVERROR_EOF && avs_has_video(avs->vi)) {
824 avisynth_next_stream(s, &st, pkt, &discard);
825 return avisynth_read_packet_video(s, pkt, discard);
832 static av_cold int avisynth_read_close(AVFormatContext *s)
834 if (ff_lock_avformat())
835 return AVERROR_UNKNOWN;
837 avisynth_context_destroy(s->priv_data);
838 ff_unlock_avformat();
842 static int avisynth_read_seek(AVFormatContext *s, int stream_index,
843 int64_t timestamp, int flags)
845 AviSynthContext *avs = s->priv_data;
847 AVRational fps, samplerate;
850 return AVERROR_UNKNOWN;
852 fps = (AVRational) { avs->vi->fps_numerator,
853 avs->vi->fps_denominator };
854 samplerate = (AVRational) { avs->vi->audio_samples_per_second, 1 };
856 st = s->streams[stream_index];
857 if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
858 /* AviSynth frame counts are signed int. */
859 if ((timestamp >= avs->vi->num_frames) ||
860 (timestamp > INT_MAX) ||
863 avs->curr_frame = timestamp;
864 if (avs_has_audio(avs->vi))
865 avs->curr_sample = av_rescale_q(timestamp, samplerate, fps);
867 if ((timestamp >= avs->vi->num_audio_samples) || (timestamp < 0))
869 /* Force frame granularity for seeking. */
870 if (avs_has_video(avs->vi)) {
871 avs->curr_frame = av_rescale_q(timestamp, fps, samplerate);
872 avs->curr_sample = av_rescale_q(avs->curr_frame, samplerate, fps);
874 avs->curr_sample = timestamp;
881 const AVInputFormat ff_avisynth_demuxer = {
883 .long_name = NULL_IF_CONFIG_SMALL("AviSynth script"),
884 .priv_data_size = sizeof(AviSynthContext),
885 .read_header = avisynth_read_header,
886 .read_packet = avisynth_read_packet,
887 .read_close = avisynth_read_close,
888 .read_seek = avisynth_read_seek,