FFmpeg/libavformat/avisynth.c
2020-04-05 01:23:46 +02:00

884 lines
27 KiB
C

/*
* AviSynth(+) support
* Copyright (c) 2012 AvxSynth Team
*
* This file is part of FFmpeg
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/attributes.h"
#include "libavutil/internal.h"
#include "libavcodec/internal.h"
#include "avformat.h"
#include "internal.h"
#include "config.h"
/* Enable function pointer definitions for runtime loading. */
#define AVSC_NO_DECLSPEC
/* Platform-specific directives. */
#ifdef _WIN32
#include "compat/w32dlfcn.h"
#undef EXTERN_C
#define AVISYNTH_LIB "avisynth"
#else
#include <dlfcn.h>
#define AVISYNTH_NAME "libavisynth"
#define AVISYNTH_LIB AVISYNTH_NAME SLIBSUF
#endif
#include <avisynth/avisynth_c.h>
typedef struct AviSynthLibrary {
void *library;
#define AVSC_DECLARE_FUNC(name) name ## _func name
AVSC_DECLARE_FUNC(avs_bit_blt);
AVSC_DECLARE_FUNC(avs_clip_get_error);
AVSC_DECLARE_FUNC(avs_create_script_environment);
AVSC_DECLARE_FUNC(avs_delete_script_environment);
AVSC_DECLARE_FUNC(avs_get_audio);
AVSC_DECLARE_FUNC(avs_get_error);
AVSC_DECLARE_FUNC(avs_get_frame);
AVSC_DECLARE_FUNC(avs_get_version);
AVSC_DECLARE_FUNC(avs_get_video_info);
AVSC_DECLARE_FUNC(avs_invoke);
AVSC_DECLARE_FUNC(avs_release_clip);
AVSC_DECLARE_FUNC(avs_release_value);
AVSC_DECLARE_FUNC(avs_release_video_frame);
AVSC_DECLARE_FUNC(avs_take_clip);
AVSC_DECLARE_FUNC(avs_bits_per_pixel);
AVSC_DECLARE_FUNC(avs_get_height_p);
AVSC_DECLARE_FUNC(avs_get_pitch_p);
AVSC_DECLARE_FUNC(avs_get_read_ptr_p);
AVSC_DECLARE_FUNC(avs_get_row_size_p);
AVSC_DECLARE_FUNC(avs_is_planar_rgb);
AVSC_DECLARE_FUNC(avs_is_planar_rgba);
#undef AVSC_DECLARE_FUNC
} AviSynthLibrary;
typedef struct AviSynthContext {
AVS_ScriptEnvironment *env;
AVS_Clip *clip;
const AVS_VideoInfo *vi;
/* avisynth_read_packet_video() iterates over this. */
int n_planes;
const int *planes;
int curr_stream;
int curr_frame;
int64_t curr_sample;
int error;
/* Linked list pointers. */
struct AviSynthContext *next;
} AviSynthContext;
static const int avs_planes_packed[1] = { 0 };
static const int avs_planes_grey[1] = { AVS_PLANAR_Y };
static const int avs_planes_yuv[3] = { AVS_PLANAR_Y, AVS_PLANAR_U,
AVS_PLANAR_V };
static const int avs_planes_rgb[3] = { AVS_PLANAR_G, AVS_PLANAR_B,
AVS_PLANAR_R };
static const int avs_planes_yuva[4] = { AVS_PLANAR_Y, AVS_PLANAR_U,
AVS_PLANAR_V, AVS_PLANAR_A };
static const int avs_planes_rgba[4] = { AVS_PLANAR_G, AVS_PLANAR_B,
AVS_PLANAR_R, AVS_PLANAR_A };
/* A conflict between C++ global objects, atexit, and dynamic loading requires
* us to register our own atexit handler to prevent double freeing. */
static AviSynthLibrary avs_library;
static int avs_atexit_called = 0;
/* Linked list of AviSynthContexts. An atexit handler destroys this list. */
static AviSynthContext *avs_ctx_list = NULL;
static av_cold void avisynth_atexit_handler(void);
static av_cold int avisynth_load_library(void)
{
avs_library.library = dlopen(AVISYNTH_LIB, RTLD_NOW | RTLD_LOCAL);
if (!avs_library.library)
return AVERROR_UNKNOWN;
#define LOAD_AVS_FUNC(name, continue_on_fail) \
avs_library.name = (name ## _func) \
dlsym(avs_library.library, #name); \
if (!continue_on_fail && !avs_library.name) \
goto fail;
LOAD_AVS_FUNC(avs_bit_blt, 0);
LOAD_AVS_FUNC(avs_clip_get_error, 0);
LOAD_AVS_FUNC(avs_create_script_environment, 0);
LOAD_AVS_FUNC(avs_delete_script_environment, 0);
LOAD_AVS_FUNC(avs_get_audio, 0);
LOAD_AVS_FUNC(avs_get_error, 1); // New to AviSynth 2.6
LOAD_AVS_FUNC(avs_get_frame, 0);
LOAD_AVS_FUNC(avs_get_version, 0);
LOAD_AVS_FUNC(avs_get_video_info, 0);
LOAD_AVS_FUNC(avs_invoke, 0);
LOAD_AVS_FUNC(avs_release_clip, 0);
LOAD_AVS_FUNC(avs_release_value, 0);
LOAD_AVS_FUNC(avs_release_video_frame, 0);
LOAD_AVS_FUNC(avs_take_clip, 0);
LOAD_AVS_FUNC(avs_bits_per_pixel, 1);
LOAD_AVS_FUNC(avs_get_height_p, 1);
LOAD_AVS_FUNC(avs_get_pitch_p, 1);
LOAD_AVS_FUNC(avs_get_read_ptr_p, 1);
LOAD_AVS_FUNC(avs_get_row_size_p, 1);
LOAD_AVS_FUNC(avs_is_planar_rgb, 1);
LOAD_AVS_FUNC(avs_is_planar_rgba, 1);
#undef LOAD_AVS_FUNC
atexit(avisynth_atexit_handler);
return 0;
fail:
dlclose(avs_library.library);
return AVERROR_UNKNOWN;
}
/* Note that avisynth_context_create and avisynth_context_destroy
* do not allocate or free the actual context! That is taken care of
* by libavformat. */
static av_cold int avisynth_context_create(AVFormatContext *s)
{
AviSynthContext *avs = s->priv_data;
int ret;
if (!avs_library.library)
if (ret = avisynth_load_library())
return ret;
avs->env = avs_library.avs_create_script_environment(3);
if (avs_library.avs_get_error) {
const char *error = avs_library.avs_get_error(avs->env);
if (error) {
av_log(s, AV_LOG_ERROR, "%s\n", error);
return AVERROR_UNKNOWN;
}
}
if (!avs_ctx_list) {
avs_ctx_list = avs;
} else {
avs->next = avs_ctx_list;
avs_ctx_list = avs;
}
return 0;
}
static av_cold void avisynth_context_destroy(AviSynthContext *avs)
{
if (avs_atexit_called)
return;
if (avs == avs_ctx_list) {
avs_ctx_list = avs->next;
} else {
AviSynthContext *prev = avs_ctx_list;
while (prev->next != avs)
prev = prev->next;
prev->next = avs->next;
}
if (avs->clip) {
avs_library.avs_release_clip(avs->clip);
avs->clip = NULL;
}
if (avs->env) {
avs_library.avs_delete_script_environment(avs->env);
avs->env = NULL;
}
}
static av_cold void avisynth_atexit_handler(void)
{
AviSynthContext *avs = avs_ctx_list;
while (avs) {
AviSynthContext *next = avs->next;
avisynth_context_destroy(avs);
avs = next;
}
dlclose(avs_library.library);
avs_atexit_called = 1;
}
/* Create AVStream from audio and video data. */
static int avisynth_create_stream_video(AVFormatContext *s, AVStream *st)
{
AviSynthContext *avs = s->priv_data;
int planar = 0; // 0: packed, 1: YUV, 2: Y8, 3: Planar RGB, 4: YUVA, 5: Planar RGBA
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
st->codecpar->width = avs->vi->width;
st->codecpar->height = avs->vi->height;
st->avg_frame_rate = (AVRational) { avs->vi->fps_numerator,
avs->vi->fps_denominator };
st->start_time = 0;
st->duration = avs->vi->num_frames;
st->nb_frames = avs->vi->num_frames;
avpriv_set_pts_info(st, 32, avs->vi->fps_denominator, avs->vi->fps_numerator);
switch (avs->vi->pixel_type) {
/* 10~16-bit YUV pix_fmts (AviSynth+) */
case AVS_CS_YUV444P10:
st->codecpar->format = AV_PIX_FMT_YUV444P10;
planar = 1;
break;
case AVS_CS_YUV422P10:
st->codecpar->format = AV_PIX_FMT_YUV422P10;
planar = 1;
break;
case AVS_CS_YUV420P10:
st->codecpar->format = AV_PIX_FMT_YUV420P10;
planar = 1;
break;
case AVS_CS_YUV444P12:
st->codecpar->format = AV_PIX_FMT_YUV444P12;
planar = 1;
break;
case AVS_CS_YUV422P12:
st->codecpar->format = AV_PIX_FMT_YUV422P12;
planar = 1;
break;
case AVS_CS_YUV420P12:
st->codecpar->format = AV_PIX_FMT_YUV420P12;
planar = 1;
break;
case AVS_CS_YUV444P14:
st->codecpar->format = AV_PIX_FMT_YUV444P14;
planar = 1;
break;
case AVS_CS_YUV422P14:
st->codecpar->format = AV_PIX_FMT_YUV422P14;
planar = 1;
break;
case AVS_CS_YUV420P14:
st->codecpar->format = AV_PIX_FMT_YUV420P14;
planar = 1;
break;
case AVS_CS_YUV444P16:
st->codecpar->format = AV_PIX_FMT_YUV444P16;
planar = 1;
break;
case AVS_CS_YUV422P16:
st->codecpar->format = AV_PIX_FMT_YUV422P16;
planar = 1;
break;
case AVS_CS_YUV420P16:
st->codecpar->format = AV_PIX_FMT_YUV420P16;
planar = 1;
break;
/* 8~16-bit YUV pix_fmts with Alpha (AviSynth+) */
case AVS_CS_YUVA444:
st->codecpar->format = AV_PIX_FMT_YUVA444P;
planar = 4;
break;
case AVS_CS_YUVA422:
st->codecpar->format = AV_PIX_FMT_YUVA422P;
planar = 4;
break;
case AVS_CS_YUVA420:
st->codecpar->format = AV_PIX_FMT_YUVA420P;
planar = 4;
break;
case AVS_CS_YUVA444P10:
st->codecpar->format = AV_PIX_FMT_YUVA444P10;
planar = 4;
break;
case AVS_CS_YUVA422P10:
st->codecpar->format = AV_PIX_FMT_YUVA422P10;
planar = 4;
break;
case AVS_CS_YUVA420P10:
st->codecpar->format = AV_PIX_FMT_YUVA420P10;
planar = 4;
break;
case AVS_CS_YUVA422P12:
st->codecpar->format = AV_PIX_FMT_YUVA422P12;
planar = 4;
break;
case AVS_CS_YUVA444P16:
st->codecpar->format = AV_PIX_FMT_YUVA444P16;
planar = 4;
break;
case AVS_CS_YUVA422P16:
st->codecpar->format = AV_PIX_FMT_YUVA422P16;
planar = 4;
break;
case AVS_CS_YUVA420P16:
st->codecpar->format = AV_PIX_FMT_YUVA420P16;
planar = 4;
break;
/* Planar RGB pix_fmts (AviSynth+) */
case AVS_CS_RGBP:
st->codecpar->format = AV_PIX_FMT_GBRP;
planar = 3;
break;
case AVS_CS_RGBP10:
st->codecpar->format = AV_PIX_FMT_GBRP10;
planar = 3;
break;
case AVS_CS_RGBP12:
st->codecpar->format = AV_PIX_FMT_GBRP12;
planar = 3;
break;
case AVS_CS_RGBP14:
st->codecpar->format = AV_PIX_FMT_GBRP14;
planar = 3;
break;
case AVS_CS_RGBP16:
st->codecpar->format = AV_PIX_FMT_GBRP16;
planar = 3;
break;
/* Single precision floating point Planar RGB (AviSynth+) */
case AVS_CS_RGBPS:
st->codecpar->format = AV_PIX_FMT_GBRPF32;
planar = 3;
break;
/* Planar RGB pix_fmts with Alpha (AviSynth+) */
case AVS_CS_RGBAP:
st->codecpar->format = AV_PIX_FMT_GBRAP;
planar = 5;
break;
case AVS_CS_RGBAP10:
st->codecpar->format = AV_PIX_FMT_GBRAP10;
planar = 5;
break;
case AVS_CS_RGBAP12:
st->codecpar->format = AV_PIX_FMT_GBRAP12;
planar = 5;
break;
case AVS_CS_RGBAP16:
st->codecpar->format = AV_PIX_FMT_GBRAP16;
planar = 5;
break;
/* Single precision floating point Planar RGB with Alpha (AviSynth+) */
case AVS_CS_RGBAPS:
st->codecpar->format = AV_PIX_FMT_GBRAPF32;
planar = 5;
break;
/* 10~16-bit gray pix_fmts (AviSynth+) */
case AVS_CS_Y10:
st->codecpar->format = AV_PIX_FMT_GRAY10;
planar = 2;
break;
case AVS_CS_Y12:
st->codecpar->format = AV_PIX_FMT_GRAY12;
planar = 2;
break;
case AVS_CS_Y14:
st->codecpar->format = AV_PIX_FMT_GRAY14;
planar = 2;
break;
case AVS_CS_Y16:
st->codecpar->format = AV_PIX_FMT_GRAY16;
planar = 2;
break;
/* Single precision floating point gray (AviSynth+) */
case AVS_CS_Y32:
st->codecpar->format = AV_PIX_FMT_GRAYF32;
planar = 2;
break;
/* pix_fmts added in AviSynth 2.6 */
case AVS_CS_YV24:
st->codecpar->format = AV_PIX_FMT_YUV444P;
planar = 1;
break;
case AVS_CS_YV16:
st->codecpar->format = AV_PIX_FMT_YUV422P;
planar = 1;
break;
case AVS_CS_YV411:
st->codecpar->format = AV_PIX_FMT_YUV411P;
planar = 1;
break;
case AVS_CS_Y8:
st->codecpar->format = AV_PIX_FMT_GRAY8;
planar = 2;
break;
/* 16-bit packed RGB pix_fmts (AviSynth+) */
case AVS_CS_BGR48:
st->codecpar->format = AV_PIX_FMT_BGR48;
break;
case AVS_CS_BGR64:
st->codecpar->format = AV_PIX_FMT_BGRA64;
break;
/* AviSynth 2.5 pix_fmts */
case AVS_CS_BGR24:
st->codecpar->format = AV_PIX_FMT_BGR24;
break;
case AVS_CS_BGR32:
st->codecpar->format = AV_PIX_FMT_RGB32;
break;
case AVS_CS_YUY2:
st->codecpar->format = AV_PIX_FMT_YUYV422;
break;
case AVS_CS_YV12:
st->codecpar->format = AV_PIX_FMT_YUV420P;
planar = 1;
break;
case AVS_CS_I420: // Is this even used anywhere?
st->codecpar->format = AV_PIX_FMT_YUV420P;
planar = 1;
break;
default:
av_log(s, AV_LOG_ERROR,
"unknown AviSynth colorspace %d\n", avs->vi->pixel_type);
avs->error = 1;
return AVERROR_UNKNOWN;
}
switch (planar) {
case 5: // Planar RGB + Alpha
avs->n_planes = 4;
avs->planes = avs_planes_rgba;
break;
case 4: // YUV + Alpha
avs->n_planes = 4;
avs->planes = avs_planes_yuva;
break;
case 3: // Planar RGB
avs->n_planes = 3;
avs->planes = avs_planes_rgb;
break;
case 2: // Y8
avs->n_planes = 1;
avs->planes = avs_planes_grey;
break;
case 1: // YUV
avs->n_planes = 3;
avs->planes = avs_planes_yuv;
break;
default:
avs->n_planes = 1;
avs->planes = avs_planes_packed;
}
return 0;
}
static int avisynth_create_stream_audio(AVFormatContext *s, AVStream *st)
{
AviSynthContext *avs = s->priv_data;
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->sample_rate = avs->vi->audio_samples_per_second;
st->codecpar->channels = avs->vi->nchannels;
st->duration = avs->vi->num_audio_samples;
avpriv_set_pts_info(st, 64, 1, avs->vi->audio_samples_per_second);
switch (avs->vi->sample_type) {
case AVS_SAMPLE_INT8:
st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
break;
case AVS_SAMPLE_INT16:
st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;
break;
case AVS_SAMPLE_INT24:
st->codecpar->codec_id = AV_CODEC_ID_PCM_S24LE;
break;
case AVS_SAMPLE_INT32:
st->codecpar->codec_id = AV_CODEC_ID_PCM_S32LE;
break;
case AVS_SAMPLE_FLOAT:
st->codecpar->codec_id = AV_CODEC_ID_PCM_F32LE;
break;
default:
av_log(s, AV_LOG_ERROR,
"unknown AviSynth sample type %d\n", avs->vi->sample_type);
avs->error = 1;
return AVERROR_UNKNOWN;
}
return 0;
}
static int avisynth_create_stream(AVFormatContext *s)
{
AviSynthContext *avs = s->priv_data;
AVStream *st;
int ret;
int id = 0;
if (avs_has_video(avs->vi)) {
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR_UNKNOWN;
st->id = id++;
if (ret = avisynth_create_stream_video(s, st))
return ret;
}
if (avs_has_audio(avs->vi)) {
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR_UNKNOWN;
st->id = id++;
if (ret = avisynth_create_stream_audio(s, st))
return ret;
}
return 0;
}
static int avisynth_open_file(AVFormatContext *s)
{
AviSynthContext *avs = s->priv_data;
AVS_Value arg, val;
int ret;
#ifdef _WIN32
char filename_ansi[MAX_PATH * 4];
wchar_t filename_wc[MAX_PATH * 4];
#endif
if (ret = avisynth_context_create(s))
return ret;
#ifdef _WIN32
/* Convert UTF-8 to ANSI code page */
MultiByteToWideChar(CP_UTF8, 0, s->url, -1, filename_wc, MAX_PATH * 4);
WideCharToMultiByte(CP_THREAD_ACP, 0, filename_wc, -1, filename_ansi,
MAX_PATH * 4, NULL, NULL);
arg = avs_new_value_string(filename_ansi);
#else
arg = avs_new_value_string(s->url);
#endif
val = avs_library.avs_invoke(avs->env, "Import", arg, 0);
if (avs_is_error(val)) {
av_log(s, AV_LOG_ERROR, "%s\n", avs_as_error(val));
ret = AVERROR_UNKNOWN;
goto fail;
}
if (!avs_is_clip(val)) {
av_log(s, AV_LOG_ERROR, "AviSynth script did not return a clip\n");
ret = AVERROR_UNKNOWN;
goto fail;
}
avs->clip = avs_library.avs_take_clip(val, avs->env);
avs->vi = avs_library.avs_get_video_info(avs->clip);
/* On Windows, FFmpeg supports AviSynth interface version 6 or higher.
* This includes AviSynth 2.6 RC1 or higher, and AviSynth+ r1718 or higher,
* and excludes 2.5 and the 2.6 alphas. */
if (avs_library.avs_get_version(avs->clip) < 6) {
av_log(s, AV_LOG_ERROR,
"AviSynth version is too old. Please upgrade to either AviSynth 2.6 >= RC1 or AviSynth+ >= r1718.\n");
ret = AVERROR_UNKNOWN;
goto fail;
}
/* Release the AVS_Value as it will go out of scope. */
avs_library.avs_release_value(val);
if (ret = avisynth_create_stream(s))
goto fail;
return 0;
fail:
avisynth_context_destroy(avs);
return ret;
}
static void avisynth_next_stream(AVFormatContext *s, AVStream **st,
AVPacket *pkt, int *discard)
{
AviSynthContext *avs = s->priv_data;
avs->curr_stream++;
avs->curr_stream %= s->nb_streams;
*st = s->streams[avs->curr_stream];
if ((*st)->discard == AVDISCARD_ALL)
*discard = 1;
else
*discard = 0;
return;
}
/* Copy AviSynth clip data into an AVPacket. */
static int avisynth_read_packet_video(AVFormatContext *s, AVPacket *pkt,
int discard)
{
AviSynthContext *avs = s->priv_data;
AVS_VideoFrame *frame;
unsigned char *dst_p;
const unsigned char *src_p;
int n, i, plane, rowsize, planeheight, pitch, bits, ret;
const char *error;
int avsplus av_unused;
if (avs->curr_frame >= avs->vi->num_frames)
return AVERROR_EOF;
/* This must happen even if the stream is discarded to prevent desync. */
n = avs->curr_frame++;
if (discard)
return 0;
#ifdef _WIN32
/* Detect whether we're using AviSynth 2.6 or AviSynth+ by
* looking for whether avs_is_planar_rgb exists. */
if (GetProcAddress(avs_library.library, "avs_is_planar_rgb") == NULL)
avsplus = 0;
else
avsplus = 1;
#else
/* AviSynth+ is now the only variant of AviSynth we support
* on Linux and macOS. */
avsplus = 1;
#endif
bits = avs_library.avs_bits_per_pixel(avs->vi);
/* Without the cast to int64_t, calculation overflows at about 9k x 9k
* resolution. */
pkt->size = (((int64_t)avs->vi->width *
(int64_t)avs->vi->height) * bits) / 8;
if (!pkt->size)
return AVERROR_UNKNOWN;
if ((ret = av_new_packet(pkt, pkt->size)) < 0)
return ret;
pkt->pts = n;
pkt->dts = n;
pkt->duration = 1;
pkt->stream_index = avs->curr_stream;
frame = avs_library.avs_get_frame(avs->clip, n);
error = avs_library.avs_clip_get_error(avs->clip);
if (error) {
av_log(s, AV_LOG_ERROR, "%s\n", error);
avs->error = 1;
av_packet_unref(pkt);
return AVERROR_UNKNOWN;
}
dst_p = pkt->data;
for (i = 0; i < avs->n_planes; i++) {
plane = avs->planes[i];
src_p = avs_library.avs_get_read_ptr_p(frame, plane);
pitch = avs_library.avs_get_pitch_p(frame, plane);
rowsize = avs_library.avs_get_row_size_p(frame, plane);
planeheight = avs_library.avs_get_height_p(frame, plane);
/* Flip RGB video. */
if (avs_is_rgb24(avs->vi) || avs_is_rgb(avs->vi)) {
src_p = src_p + (planeheight - 1) * pitch;
pitch = -pitch;
}
/* Flip Planar RGB video */
if (avsplus && (avs_library.avs_is_planar_rgb(avs->vi) ||
avs_library.avs_is_planar_rgba(avs->vi))) {
src_p = src_p + (planeheight - 1) * pitch;
pitch = -pitch;
}
avs_library.avs_bit_blt(avs->env, dst_p, rowsize, src_p, pitch,
rowsize, planeheight);
dst_p += rowsize * planeheight;
}
avs_library.avs_release_video_frame(frame);
return 0;
}
static int avisynth_read_packet_audio(AVFormatContext *s, AVPacket *pkt,
int discard)
{
AviSynthContext *avs = s->priv_data;
AVRational fps, samplerate;
int samples, ret;
int64_t n;
const char *error;
if (avs->curr_sample >= avs->vi->num_audio_samples)
return AVERROR_EOF;
fps.num = avs->vi->fps_numerator;
fps.den = avs->vi->fps_denominator;
samplerate.num = avs->vi->audio_samples_per_second;
samplerate.den = 1;
if (avs_has_video(avs->vi)) {
if (avs->curr_frame < avs->vi->num_frames)
samples = av_rescale_q(avs->curr_frame, samplerate, fps) -
avs->curr_sample;
else
samples = av_rescale_q(1, samplerate, fps);
} else {
samples = 1000;
}
/* After seeking, audio may catch up with video. */
if (samples <= 0) {
pkt->size = 0;
pkt->data = NULL;
return 0;
}
if (avs->curr_sample + samples > avs->vi->num_audio_samples)
samples = avs->vi->num_audio_samples - avs->curr_sample;
/* This must happen even if the stream is discarded to prevent desync. */
n = avs->curr_sample;
avs->curr_sample += samples;
if (discard)
return 0;
pkt->size = avs_bytes_per_channel_sample(avs->vi) *
samples * avs->vi->nchannels;
if (!pkt->size)
return AVERROR_UNKNOWN;
if ((ret = av_new_packet(pkt, pkt->size)) < 0)
return ret;
pkt->pts = n;
pkt->dts = n;
pkt->duration = samples;
pkt->stream_index = avs->curr_stream;
avs_library.avs_get_audio(avs->clip, pkt->data, n, samples);
error = avs_library.avs_clip_get_error(avs->clip);
if (error) {
av_log(s, AV_LOG_ERROR, "%s\n", error);
avs->error = 1;
av_packet_unref(pkt);
return AVERROR_UNKNOWN;
}
return 0;
}
static av_cold int avisynth_read_header(AVFormatContext *s)
{
int ret;
// Calling library must implement a lock for thread-safe opens.
if (ret = ff_lock_avformat())
return ret;
if (ret = avisynth_open_file(s)) {
ff_unlock_avformat();
return ret;
}
ff_unlock_avformat();
return 0;
}
static int avisynth_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AviSynthContext *avs = s->priv_data;
AVStream *st;
int discard = 0;
int ret;
if (avs->error)
return AVERROR_UNKNOWN;
/* If either stream reaches EOF, try to read the other one before
* giving up. */
avisynth_next_stream(s, &st, pkt, &discard);
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
ret = avisynth_read_packet_video(s, pkt, discard);
if (ret == AVERROR_EOF && avs_has_audio(avs->vi)) {
avisynth_next_stream(s, &st, pkt, &discard);
return avisynth_read_packet_audio(s, pkt, discard);
}
} else {
ret = avisynth_read_packet_audio(s, pkt, discard);
if (ret == AVERROR_EOF && avs_has_video(avs->vi)) {
avisynth_next_stream(s, &st, pkt, &discard);
return avisynth_read_packet_video(s, pkt, discard);
}
}
return ret;
}
static av_cold int avisynth_read_close(AVFormatContext *s)
{
if (ff_lock_avformat())
return AVERROR_UNKNOWN;
avisynth_context_destroy(s->priv_data);
ff_unlock_avformat();
return 0;
}
static int avisynth_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
AviSynthContext *avs = s->priv_data;
AVStream *st;
AVRational fps, samplerate;
if (avs->error)
return AVERROR_UNKNOWN;
fps = (AVRational) { avs->vi->fps_numerator,
avs->vi->fps_denominator };
samplerate = (AVRational) { avs->vi->audio_samples_per_second, 1 };
st = s->streams[stream_index];
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
/* AviSynth frame counts are signed int. */
if ((timestamp >= avs->vi->num_frames) ||
(timestamp > INT_MAX) ||
(timestamp < 0))
return AVERROR_EOF;
avs->curr_frame = timestamp;
if (avs_has_audio(avs->vi))
avs->curr_sample = av_rescale_q(timestamp, samplerate, fps);
} else {
if ((timestamp >= avs->vi->num_audio_samples) || (timestamp < 0))
return AVERROR_EOF;
/* Force frame granularity for seeking. */
if (avs_has_video(avs->vi)) {
avs->curr_frame = av_rescale_q(timestamp, fps, samplerate);
avs->curr_sample = av_rescale_q(avs->curr_frame, samplerate, fps);
} else {
avs->curr_sample = timestamp;
}
}
return 0;
}
AVInputFormat ff_avisynth_demuxer = {
.name = "avisynth",
.long_name = NULL_IF_CONFIG_SMALL("AviSynth script"),
.priv_data_size = sizeof(AviSynthContext),
.read_header = avisynth_read_header,
.read_packet = avisynth_read_packet,
.read_close = avisynth_read_close,
.read_seek = avisynth_read_seek,
.extensions = "avs",
};