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Use gop size for perPage results. #3

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This commit is contained in:
Alf
2020-12-22 22:33:39 -08:00
parent c152e9f0eb
commit 7854c0ad73
3 changed files with 28 additions and 12 deletions
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18
src/ffprobe-wasm-wrapper.cpp
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@@ -64,6 +64,7 @@ typedef struct FileInfoResponse {
typedef struct FramesResponse {
std::vector<Frame> frames;
int nb_frames;
int gop_size;
} FramesResponse;
FileInfoResponse get_file_info(std::string filename) {
@@ -200,8 +201,10 @@ FramesResponse get_frames(std::string filename, int offset) {
AVPacket *pPacket = av_packet_alloc();
AVFrame *pFrame = av_frame_alloc();
int how_many_packets_to_process = 48; // per page.
int frame_count = 1;
int max_packets_to_process = 1000;
int frame_count = 0;
int key_frames = 0;
int gop_size = 0;
// Read video frames.
while (av_read_frame(pFormatContext, pPacket) >= 0) {
@@ -217,6 +220,12 @@ FramesResponse get_frames(std::string filename, int offset) {
continue;
}
// Track keyframes so we paginate by each GOP.
if (pFrame->key_frame == 1) key_frames++;
// Break at the next keyframe found.
if (key_frames > 1) break;
Frame f = {
.frame_number = frame_count,
.pict_type = (char) av_get_picture_type_char(pFrame->pict_type),
@@ -226,7 +235,7 @@ FramesResponse get_frames(std::string filename, int offset) {
};
r.frames.push_back(f);
if (--how_many_packets_to_process <= 0) break;
if (--max_packets_to_process <= 0) break;
}
}
frame_count++;
@@ -237,6 +246,8 @@ FramesResponse get_frames(std::string filename, int offset) {
av_packet_free(&pPacket);
av_frame_free(&pFrame);
avcodec_free_context(&pCodecContext);
r.gop_size = frame_count - offset;
return r;
}
@@ -287,6 +298,7 @@ EMSCRIPTEN_BINDINGS(structs) {
emscripten::value_object<FramesResponse>("FramesResponse")
.field("frames", &FramesResponse::frames)
.field("nb_frames", &FramesResponse::nb_frames)
.field("gop_size", &FramesResponse::gop_size)
;
function("get_frames", &get_frames);
}