diff --git a/ffmpeg/ffmpeg.c b/ffmpeg/ffmpeg.c
index 110e938..2e5db34 100644
--- a/ffmpeg/ffmpeg.c
+++ b/ffmpeg/ffmpeg.c
@@ -257,30 +257,11 @@ obtain_next_frame(AVFormatContext *fmt_ctx, AVCodecContext *dec_ctx, int stream_
     return err;
 }
 
-int64_t find_duration(AVFormatContext *fmt_ctx) {
-    AVPacket pkt = create_packet();
-    int err = 0;
-    int64_t duration = 0;
-    while (err >= 0) {
-        err = av_read_frame(fmt_ctx, &pkt);
-        if (pkt.pts != AV_NOPTS_VALUE) {
-            AVRational time_base = fmt_ctx->streams[pkt.stream_index]->time_base;
-            duration = FFMAX(duration, pkt.pts * 1000000000 * time_base.num / time_base.den);
-        }
-        av_packet_unref(&pkt);
-    }
-    if (err == AVERROR_EOF) {
-        return duration;
-    }
-    return err;
-}
-
 ThumbContext *create_thumb_context(AVStream *stream, AVFrame *frame) {
     ThumbContext *thumb_ctx = av_mallocz(sizeof *thumb_ctx);
     if (!thumb_ctx) {
         return thumb_ctx;
     }
-//    thumb_ctx->n = 0;
     thumb_ctx->desc = av_pix_fmt_desc_get(frame->format);
     int nb_frames = 100;
     if (stream->disposition & AV_DISPOSITION_ATTACHED_PIC) {
diff --git a/ffmpeg/ffmpeg.go b/ffmpeg/ffmpeg.go
index caf5b92..168e73e 100644
--- a/ffmpeg/ffmpeg.go
+++ b/ffmpeg/ffmpeg.go
@@ -6,7 +6,6 @@ package ffmpeg
 // #include "ffmpeg.h"
 import "C"
 import (
-	"context"
 	"github.com/cshum/imagor/vips/pointer"
 	"io"
 	"math"
@@ -35,7 +34,6 @@ type Metadata struct {
 }
 
 type AVContext struct {
-	context            context.Context
 	opaque             unsafe.Pointer
 	reader             io.Reader
 	seeker             io.Seeker
diff --git a/ffmpeg/ffmpeg.h b/ffmpeg/ffmpeg.h
index c056244..180fbd5 100644
--- a/ffmpeg/ffmpeg.h
+++ b/ffmpeg/ffmpeg.h
@@ -52,8 +52,6 @@ AVPacket create_packet();
 int
 obtain_next_frame(AVFormatContext *fmt_ctx, AVCodecContext *dec_ctx, int stream_index, AVPacket *pkt, AVFrame **frame);
 
-int64_t find_duration(AVFormatContext *fmt_ctx);
-
 ThumbContext *create_thumb_context(AVStream *stream, AVFrame *frame);
 
 void free_thumb_context(ThumbContext *thumb_ctx);