diff --git a/Cargo.toml b/Cargo.toml
index ccba9f9..5b895dd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,7 @@ edition = "2018"
 bitreader = "0.3.1"
 memchr = "2.1.1"
 rfc6381-codec = "0.1"
+log = "0.4"
 
 [dev-dependencies]
 hex-literal = "0.2.1"
diff --git a/src/annexb.rs b/src/annexb.rs
index d9ca1fd..eaa23b7 100644
--- a/src/annexb.rs
+++ b/src/annexb.rs
@@ -3,6 +3,7 @@
 
 use crate::Context;
 use memchr;
+use log::*;
 
 #[derive(Debug)]
 enum ParseState {
@@ -95,7 +96,7 @@ impl<R, Ctx> AnnexBReader<R, Ctx>
             let b = buf[i];
             match self.state {
                 ParseState::End => {
-                    eprintln!("no previous call to start()");
+                    error!("no previous call to start()");
                     self.state = ParseState::Error;
                     return;
                 },
@@ -214,7 +215,7 @@ impl<R, Ctx> AnnexBReader<R, Ctx>
                             self.to(ParseState::InUnitStart);
                         },
                         _ => {
-                            eprintln!("Expected either start code byte 0x01 or end_units(), got byte {:#x}", b);
+                            error!("Expected either start code byte 0x01 or end_units(), got byte {:#x}", b);
                             self.to(ParseState::Error);
                         },
                     }
@@ -273,12 +274,12 @@ impl<R, Ctx> AnnexBReader<R, Ctx>
             };
             self.nal_reader.push(ctx, &buf[start..end_index])
         } else {
-            eprintln!("AnnexBReader: no start_index");
+            error!("AnnexBReader: no start_index");
         }
     }
 
     fn err(&mut self, b: u8) {
-        eprintln!("AnnexBReader: state={:?}, invalid byte {:#x}", self.state, b);
+        error!("AnnexBReader: state={:?}, invalid byte {:#x}", self.state, b);
         self.state = ParseState::Start;
     }
 }
diff --git a/src/nal/mod.rs b/src/nal/mod.rs
index c3e9e00..d4a325e 100644
--- a/src/nal/mod.rs
+++ b/src/nal/mod.rs
@@ -13,6 +13,7 @@ use crate::annexb::NalReader;
 use std::cell::RefCell;
 use crate::Context;
 use std::fmt;
+use log::*;
 
 #[derive(PartialEq, Hash, Debug, Copy, Clone)]
 pub enum UnitType {
@@ -210,7 +211,7 @@ impl<Ctx> NalReader for NalSwitch<Ctx> {
                     },
                     Err(e) => {
                         // TODO: proper error propagation
-                        eprintln!("Bad NAL header: {:?}", e);
+                        error!("Bad NAL header: {:?}", e);
                         NalSwitchState::Ignoring
                     }
                 };
diff --git a/src/nal/pps.rs b/src/nal/pps.rs
index c87c246..b5fed24 100644
--- a/src/nal/pps.rs
+++ b/src/nal/pps.rs
@@ -5,6 +5,7 @@ use super::sps;
 use std::marker;
 use crate::{rbsp, Context};
 use crate::rbsp::RbspBitReader;
+use log::*;
 
 #[derive(Debug)]
 pub enum PpsError {
@@ -301,7 +302,7 @@ impl<Ctx> NalHandler for PicParameterSetNalHandler<Ctx> {
                 ctx.put_pic_param_set(pps);
             },
             Err(e) => {
-                eprintln!("pps: {:?}", e);
+                error!("pps: {:?}", e);
             },
         }
     }
diff --git a/src/nal/sei/buffering_period.rs b/src/nal/sei/buffering_period.rs
index 2b3bbb0..6882ed8 100644
--- a/src/nal/sei/buffering_period.rs
+++ b/src/nal/sei/buffering_period.rs
@@ -5,6 +5,7 @@ use crate::nal::pps;
 use crate::rbsp::RbspBitReader;
 use crate::Context;
 use crate::nal::sei::HeaderType;
+use log::*;
 
 #[derive(Debug)]
 enum BufferingPeriodError {
@@ -94,9 +95,9 @@ impl<Ctx> SeiCompletePayloadReader for BufferingPeriodPayloadReader<Ctx> {
     fn header(&mut self, ctx: &mut Context<Ctx>, payload_type: HeaderType, buf: &[u8]) {
         assert_eq!(payload_type, HeaderType::BufferingPeriod);
         match BufferingPeriod::read(ctx, buf) {
-            Err(e) => eprintln!("Failure reading buffering_period: {:?}", e),
+            Err(e) => error!("Failure reading buffering_period: {:?}", e),
             Ok(buffering_period) => {
-println!("buffering_period {:#?}", buffering_period);
+                info!("TODO: expose buffering_period {:#?}", buffering_period);
             }
         }
     }
diff --git a/src/nal/sei/mod.rs b/src/nal/sei/mod.rs
index 3d53687..84fce9b 100644
--- a/src/nal/sei/mod.rs
+++ b/src/nal/sei/mod.rs
@@ -6,6 +6,7 @@ use crate::Context;
 use crate::nal::NalHandler;
 use crate::nal::NalHeader;
 use crate::rbsp::RbspDecoder;
+use log::*;
 
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub enum HeaderType {
@@ -370,15 +371,15 @@ impl<R: SeiIncrementalPayloadReader> NalHandler for SeiHeaderReader<R> {
                 //       be 0b10000000 in an SEI payload since SEI messages are byte-aligned).
             },
             SeiHeaderState::PayloadType { .. } => {
-                eprintln!("End of SEI data encountered while reading SEI payloadType");
+                error!("End of SEI data encountered while reading SEI payloadType");
                 self.reader.reset(ctx);
             },
             SeiHeaderState::PayloadSize { .. } => {
-                eprintln!("End of SEI data encountered while reading SEI payloadSize");
+                error!("End of SEI data encountered while reading SEI payloadSize");
                 self.reader.reset(ctx);
             },
             SeiHeaderState::Payload { payload_type, payload_size, consumed_size } => {
-                eprintln!("End of SEI data encountered having read {} bytes of payloadSize={} for header type {:?}", consumed_size, payload_size, payload_type);
+                error!("End of SEI data encountered having read {} bytes of payloadSize={} for header type {:?}", consumed_size, payload_size, payload_type);
                 self.reader.reset(ctx);
             },
         }
diff --git a/src/nal/sei/pic_timing.rs b/src/nal/sei/pic_timing.rs
index 4fea2ef..35202bb 100644
--- a/src/nal/sei/pic_timing.rs
+++ b/src/nal/sei/pic_timing.rs
@@ -6,6 +6,7 @@ use crate::rbsp::RbspBitReader;
 use crate::nal::sps;
 use crate::rbsp::RbspBitReaderError;
 use bitreader::BitReaderError;
+use log::*;
 
 // FIXME: SPS selection
 //      We should really wait until we know what SPS is in use by the frame which follows the
@@ -331,7 +332,7 @@ impl<H: PicTimingHandler> SeiCompletePayloadReader for PicTimingReader<H> {
     fn header(&mut self, ctx: &mut Context<Self::Ctx>, payload_type: HeaderType, buf: &[u8]) {
         assert_eq!(payload_type, HeaderType::PicTiming);
         match PicTiming::read(ctx, buf) {
-            Err(e) => eprintln!("Failure reading pic_timing: {:?}", e),
+            Err(e) => error!("Failure reading pic_timing: {:?}", e),
             Ok(pic_timing) => {
                 self.handler.handle(ctx, pic_timing);
             }
diff --git a/src/nal/sei/user_data_registered_itu_t_t35.rs b/src/nal/sei/user_data_registered_itu_t_t35.rs
index 1f0a545..c401ef9 100644
--- a/src/nal/sei/user_data_registered_itu_t_t35.rs
+++ b/src/nal/sei/user_data_registered_itu_t_t35.rs
@@ -1,6 +1,7 @@
 use crate::nal::sei::HeaderType;
 use crate::Context;
 use crate::nal::sei::SeiCompletePayloadReader;
+use log::*;
 
 #[derive(Debug)]
 pub enum ItuTT35Error {
@@ -447,7 +448,7 @@ impl<R: Register> SeiCompletePayloadReader for UserDataRegisteredItuTT35Reader<R
                 self.register.handle(ctx, country_code, payload);
             },
             Err(e) => {
-                eprintln!("Failed to read user_data_registered_itu_t_t35 header: {:?}", e);
+                error!("Failed to read user_data_registered_itu_t_t35 header: {:?}", e);
             }
         }
     }
diff --git a/src/nal/slice/mod.rs b/src/nal/slice/mod.rs
index 9b9fb62..50fab22 100644
--- a/src/nal/slice/mod.rs
+++ b/src/nal/slice/mod.rs
@@ -9,6 +9,7 @@ use crate::nal::sps;
 use std::marker;
 use crate::nal::sps::SeqParameterSet;
 use crate::nal::NalHeader;
+use log::*;
 
 enum ParseState {
     Unstarted,
@@ -542,7 +543,6 @@ impl<Ctx> super::NalHandler for SliceLayerWithoutPartitioningRbsp<Ctx> {
     type Ctx = Ctx;
 
     fn start(&mut self, _ctx: &mut Context<Ctx>, header: NalHeader) {
-        println!("SliceLayerWithoutPartitioningRbsp: start()");
         self.state = ParseState::Start(header);
     }
 
@@ -552,8 +552,8 @@ impl<Ctx> super::NalHandler for SliceLayerWithoutPartitioningRbsp<Ctx> {
             ParseState::Start(header) => {
                 let mut r = RbspBitReader::new(buf);
                 match SliceHeader::read(ctx, &mut r, header) {
-                    Ok(header) => println!("{:#?}", header),
-                    Err(e) => println!("slice_header() error: SliceHeaderError::{:?}", e),
+                    Ok(header) => info!("TODO: expose to caller: {:#?}", header),
+                    Err(e) => error!("slice_header() error: SliceHeaderError::{:?}", e),
                 }
                 self.state = ParseState::Continue(header);
             },
@@ -564,7 +564,7 @@ impl<Ctx> super::NalHandler for SliceLayerWithoutPartitioningRbsp<Ctx> {
     }
 
     fn end(&mut self, _ctx: &mut Context<Ctx>) {
-        println!("SliceLayerWithoutPartitioningRbsp: end()");
+        // TODO
     }
 }
 impl<Ctx> Default for SliceLayerWithoutPartitioningRbsp<Ctx> {
diff --git a/src/rbsp.rs b/src/rbsp.rs
index 6ffbc06..75bc2a5 100644
--- a/src/rbsp.rs
+++ b/src/rbsp.rs
@@ -26,6 +26,7 @@ use std::ops::{Deref, DerefMut};
 use bitreader;
 use crate::nal::{NalHandler, NalHeader};
 use crate::Context;
+use log::*;
 
 #[derive(Debug)]
 enum ParseState {
@@ -76,7 +77,7 @@ impl<R> RbspDecoder<R>
         if let Some(start) = start_index {
             self.nal_reader.push(ctx, &buf[start..end_index])
         } else {
-            eprintln!("RbspDecoder: no start_index");
+            error!("RbspDecoder: no start_index");
         }
     }