fix: update example

src/decode.rs

@@ -1,6 +1,5 @@
 use crate::{options_to_dict, return_ffmpeg_error, rstr, StreamInfoChannel};
 use std::collections::{HashMap, HashSet};
-use std::ffi::CStr;
 use std::fmt::{Display, Formatter};
 use std::ptr;
 

src/filter.rs

@@ -1,13 +1,12 @@
 use crate::{cstr, return_ffmpeg_error, rstr, set_opts};
 use anyhow::Error;
 use ffmpeg_sys_the_third::{
-    av_free, av_strdup, avfilter_get_by_name, avfilter_graph_alloc, avfilter_graph_alloc_filter,
+    av_strdup, avfilter_get_by_name, avfilter_graph_alloc, avfilter_graph_alloc_filter,
     avfilter_graph_config, avfilter_graph_create_filter, avfilter_graph_dump, avfilter_graph_parse,
     avfilter_inout_alloc, AVFilterContext, AVFilterGraph, AVFrame,
 };
 use log::debug;
 use std::collections::HashMap;
-use std::ffi::CStr;
 use std::ptr;
 
 pub struct Filter {

src/lib.rs

@@ -5,7 +5,6 @@ use ffmpeg_sys_the_third::{
     AV_OPT_SEARCH_CHILDREN,
 };
 use std::collections::HashMap;
-use std::ffi::CStr;
 use std::ptr;
 
 mod decode;

src/stream_info.rs

@@ -2,7 +2,6 @@ use crate::{format_time, rstr};
 use ffmpeg_sys_the_third::{
     av_get_pix_fmt_name, av_get_sample_fmt_name, avcodec_get_name, AVMediaType, AVStream,
 };
-use std::ffi::CStr;
 use std::fmt::{Display, Formatter};
 use std::intrinsics::transmute;