matrix_thing/include/matrix/video_thumbnail_maker.hpp

118 lines
4.1 KiB
C++

/**
This file is a part of rexy's matrix client
Copyright (C) 2019 rexy712
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
# include "libav/frame.hpp"
# include "libav/codec/context.hpp"
# include "libav/fmt/context.hpp"
# include "libav/packet.hpp"
extern "C"{
# include <libswscale/swscale.h> //sws_scale
# include <libavutil/imgutils.h> //av_image_alloc
}
#include <cstdlib> //size_t
namespace matrix::internal{
static libavcodec::context _get_libav_jpg_context(AVRational src, size_t w, size_t h){
AVCodec* jpg_codec = avcodec_find_encoder(AV_CODEC_ID_MJPEG);
libavcodec::context jctx(jpg_codec);
jctx->pix_fmt = AV_PIX_FMT_YUVJ420P;
jctx->width = w;
jctx->height = h;
jctx->codec_id = AV_CODEC_ID_MJPEG;
jctx->codec_type = AVMEDIA_TYPE_VIDEO;
if(src.num == 0 || src.den == 0)
jctx->time_base = AVRational{1, 30};
else
jctx->time_base = src;
jctx.open();
return jctx;
}
[[maybe_unused]]
static void _change_color_range(SwsContext* sws_ctx){
int dummy[4];
int src_range, dest_range;
int br, con, sat;
sws_getColorspaceDetails(sws_ctx, (int**)&dummy, &src_range, (int**)&dummy, &dest_range, &br, &con, &sat);
const int* coefs = sws_getCoefficients(SWS_CS_DEFAULT);
src_range = 2;
sws_setColorspaceDetails(sws_ctx, coefs, src_range, coefs, dest_range, br, con, sat);
}
static void _calc_video_thumbnail_dims(size_t target, size_t src_w, size_t src_h, size_t* w, size_t* h){
size_t target_width = src_w;
size_t target_height = src_h;
if(target_width > target_height){
if(target_width > target){
target_height = target_height * ((float)target / target_width);
target_width = target;
}
}else{
if(target_height > target){
target_width = target_width * ((float)target / target_height);
target_height = target;
}
}
*w = target_width;
*h = target_height;
}
static libav::packet _create_video_thumbnail(libavfmt::input_context& src, libavcodec::context& src_ctx, int index, size_t targw, size_t targh){
libavcodec::context jpg_context = _get_libav_jpg_context(src_ctx->time_base, targw, targh);
libav::frame src_frame(src_ctx->width, src_ctx->height, src_ctx->pix_fmt);
libav::frame jpg_frame(src_ctx->width, src_ctx->height, jpg_context->pix_fmt);
libav::packet packet;
SwsContext* sws_ctx = sws_getContext(src_ctx->width, src_ctx->height, src_ctx->pix_fmt,
targw, targh, AV_PIX_FMT_YUV420P,
SWS_BILINEAR, NULL, NULL, NULL);
//_change_color_range(sws_ctx);
av_image_alloc(jpg_frame->data, jpg_frame->linesize, targw, targh, jpg_context->pix_fmt, 32);
jpg_frame.set_freep();
while(av_read_frame(src, packet) >= 0){
if(packet->stream_index == index){
avcodec_send_packet(src_ctx, packet);
if(avcodec_receive_frame(src_ctx, src_frame) >= 0)
break;
}
av_packet_unref(packet);
}
sws_scale(sws_ctx, src_frame->data, src_frame->linesize, 0, src_ctx->height, jpg_frame->data, jpg_frame->linesize);
sws_freeContext(sws_ctx);
if(avcodec_send_frame(jpg_context, jpg_frame) < 0){
return libav::packet(nullptr);
}
if(avcodec_receive_packet(jpg_context, packet) < 0){
return libav::packet(nullptr);
}
return packet;
}
static raii::string get_libav_mimetype(const libav::fmt::input_context& ctx){
const char* first = strstr(ctx->iformat->name, ",");
if(first)
return raii::string("video/" + raii::static_string(ctx->iformat->name, first - ctx->iformat->name));
return raii::string("video/" + raii::static_string(ctx->iformat->name));
}
}
#endif