diff --git a/Project.toml b/Project.toml
index 850b570..29455b6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -9,10 +9,10 @@ BGZFStreams = "28d598bf-9b8f-59f1-b38c-5a06b4a0f5e6"
 BioAlignments = "00701ae9-d1dc-5365-b64a-a3a3ebf5695e"
 BioGenerics = "47718e42-2ac5-11e9-14af-e5595289c2ea"
 BioSequences = "7e6ae17a-c86d-528c-b3b9-7f778a29fe59"
-BufferedStreams = "e1450e63-4bb3-523b-b2a4-4ffa8c0fd77d"
 GenomicFeatures = "899a7d2d-5c61-547b-bef9-6698a8d05446"
 Indexes = "4ffb77ac-cb80-11e8-1b35-4b78cc642f6d"
 Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
+TranscodingStreams = "3bb67fe8-82b1-5028-8e26-92a6c54297fa"
 
 [compat]
 Automa = "0.7, 0.8"
@@ -20,9 +20,9 @@ BGZFStreams = "0.3"
 BioAlignments = "2"
 BioGenerics = "0.1"
 BioSequences = "2"
-BufferedStreams = "1"
 GenomicFeatures = "2"
 Indexes = "0.1"
+TranscodingStreams = "0.6, 0.7, 0.8, 0.9"
 julia = "1.1"
 
 [extras]
diff --git a/src/sam/reader.jl b/src/sam/reader.jl
index 0406165..3270957 100644
--- a/src/sam/reader.jl
+++ b/src/sam/reader.jl
@@ -1,16 +1,22 @@
 # SAM Reader
 # =========
 
-mutable struct Reader <: BioGenerics.IO.AbstractReader
-    state::State
+mutable struct Reader{S <: TranscodingStream} <: BioGenerics.IO.AbstractReader
+    state::State{S}
     header::Header
+end
 
-    function Reader(input::BufferedStreams.BufferedInputStream)
-        reader = new(State(sam_header_machine.start_state, input), Header())
-        readheader!(reader)
-        reader.state.cs = sam_body_machine.start_state
-        return reader
-    end
+function Reader(state::State{S}) where {S <: TranscodingStream}
+
+    rdr = Reader(state, Header())
+
+    cs, ln, f = readheader!(rdr.state.stream, rdr.header, (sam_machine_header.start_state, rdr.state.linenum))
+
+    rdr.state.state = sam_machine_body.start_state
+    rdr.state.linenum = ln
+    rdr.state.filled = false
+
+    return rdr
 end
 
 """
@@ -22,7 +28,19 @@ Create a data reader of the SAM file format.
 * `input`: data source
 """
 function Reader(input::IO)
-    return Reader(BufferedStreams.BufferedInputStream(input))
+
+    if input isa TranscodingStream
+        return Reader(State(input, 1, 1, false))
+    end
+
+    stream = TranscodingStreams.NoopStream(input)
+
+    return Reader(State(stream, 1, 1, false))
+
+end
+
+function Base.eltype(::Type{<:Reader})
+    return Record
 end
 
 function BioGenerics.IO.stream(reader::Reader)
@@ -38,6 +56,42 @@ function header(reader::Reader)::Header
     return reader.header
 end
 
-function Base.eltype(::Type{Reader})
-    return Record
+function Base.close(reader::Reader)
+    if reader.state.stream isa IO
+        close(reader.state.stream)
+    end
+    return nothing
+end
+
+function index!(record::MetaInfo)
+    stream = TranscodingStreams.NoopStream(IOBuffer(record.data))
+    found = index!(stream, record)
+    if !found
+        throw(ArgumentError("invalid SAM metadata"))
+    end
+    return record
+end
+
+function index!(record::Record)
+    stream = TranscodingStreams.NoopStream(IOBuffer(record.data))
+    found = index!(stream, record)
+    if !found
+        throw(ArgumentError("invalid SAM record"))
+    end
+    return record
+end
+
+function Base.read!(rdr::Reader, rec::Record)
+
+    cs, ln, f = readrecord!(rdr.state.stream, rec, (rdr.state.state, rdr.state.linenum))
+
+    rdr.state.state = cs
+    rdr.state.linenum = ln
+    rdr.state.filled = f
+
+    if !f
+        cs == 0 && throw(EOFError())
+        throw(ArgumentError("malformed SAM file"))
+    end
+    return rec
 end
diff --git a/src/sam/readrecord.jl b/src/sam/readrecord.jl
index 82ebb93..e7ea75f 100644
--- a/src/sam/readrecord.jl
+++ b/src/sam/readrecord.jl
@@ -1,179 +1,10 @@
-@inline function anchor!(stream::BufferedStreams.BufferedInputStream, p, immobilize = true)
-    stream.anchor = p
-    stream.immobilized = immobilize
-    return stream
-end
-
-@inline function upanchor!(stream::BufferedStreams.BufferedInputStream)
-    @assert stream.anchor != 0 "upanchor! called with no anchor set"
-    anchor = stream.anchor
-    stream.anchor = 0
-    stream.immobilized = false
-    return anchor
-end
-
-function ensure_margin!(stream::BufferedStreams.BufferedInputStream)
-    if stream.position * 20 > length(stream.buffer) * 19
-        BufferedStreams.shiftdata!(stream)
-    end
-    return nothing
-end
-
-@inline function resize_and_copy!(dst::Vector{UInt8}, src::Vector{UInt8}, r::UnitRange{Int})
-    return resize_and_copy!(dst, 1, src, r)
-end
-
-@inline function resize_and_copy!(dst::Vector{UInt8}, dstart::Int, src::Vector{UInt8}, r::UnitRange{Int})
-    rlen = length(r)
-    if length(dst) != dstart + rlen - 1
-        resize!(dst, dstart + rlen - 1)
-    end
-    copyto!(dst, dstart, src, first(r), rlen)
-    return dst
-end
-
-function generate_index_function(record_type, machine, init_code, actions; kwargs...)
-    kwargs = Dict(kwargs)
-    context = Automa.CodeGenContext(
-        generator = get(kwargs, :generator, :goto),
-        checkbounds = get(kwargs, :checkbounds, false),
-        loopunroll = get(kwargs, :loopunroll, 0)
-    )
-    quote
-        function index!(record::$(record_type))
-            data = record.data
-            p = 1
-            p_end = p_eof = sizeof(data)
-            initialize!(record)
-            $(init_code)
-            cs = $(machine.start_state)
-            $(Automa.generate_exec_code(context, machine, actions))
-            if cs != 0
-                throw(ArgumentError(string("failed to index ", $(record_type), " ~>", repr(String(data[p:min(p+7,p_end)])))))
-            end
-            @assert isfilled(record)
-            return record
-        end
-    end
-end
-
-function generate_readheader_function(reader_type, metainfo_type, machine, init_code, actions, finish_code=:())
-    quote
-        function readheader!(reader::$(reader_type))
-            _readheader!(reader, reader.state)
-        end
-
-        function _readheader!(reader::$(reader_type), state::State)
-            stream = state.stream
-            ensure_margin!(stream)
-            cs = state.cs
-            linenum = state.linenum
-            data = stream.buffer
-            p = stream.position
-            p_end = stream.available
-            p_eof = -1
-            finish_header = false
-            record = $(metainfo_type)()
-
-            $(init_code)
-
-            while true
-                $(Automa.generate_exec_code(Automa.CodeGenContext(generator=:table), machine, actions))
-
-                state.cs = cs
-                state.finished = cs == 0
-                state.linenum = linenum
-                stream.position = p
-
-                if cs < 0
-                    error("$($(reader_type)) file format error on line ", linenum)
-                elseif finish_header
-                    $(finish_code)
-                    break
-                elseif p > p_eof ≥ 0
-                    error("incomplete $($(reader_type)) input on line ", linenum)
-                else
-                    hits_eof = BufferedStreams.fillbuffer!(stream) == 0
-                    p = stream.position
-                    p_end = stream.available
-                    if hits_eof
-                        p_eof = p_end
-                    end
-                end
-            end
-        end
-    end
-end
-
-function generate_read_function(reader_type, machine, init_code, actions; kwargs...)
-    kwargs = Dict(kwargs)
-    context = Automa.CodeGenContext(
-        generator=get(kwargs, :generator, :goto),
-        checkbounds=get(kwargs, :checkbounds, false),
-        loopunroll=get(kwargs, :loopunroll, 0)
-    )
-    quote
-        function Base.read!(reader::$(reader_type), record::eltype($(reader_type)))::eltype($(reader_type))
-            return _read!(reader, reader.state, record)
-        end
-
-        function _read!(reader::$(reader_type), state::State, record::eltype($(reader_type)))
-            stream = state.stream
-            ensure_margin!(stream)
-            cs = state.cs
-            linenum = state.linenum
-            data = stream.buffer
-            p = stream.position
-            p_end = stream.available
-            p_eof = -1
-            found_record = false
-            initialize!(record)
-
-            $(init_code)
-
-            if state.finished
-                throw(EOFError())
-            end
-
-            while true
-                $(Automa.generate_exec_code(context, machine, actions))
-
-                state.cs = cs
-                state.finished |= cs == 0
-                state.linenum = linenum
-                stream.position = p
-
-                if cs < 0
-                    error($(reader_type), " file format error on line ", linenum, " ~>", repr(String(data[p:min(p+7,p_end)])))
-                elseif found_record
-                    break
-                elseif cs == 0
-                    throw(EOFError())
-                elseif p > p_eof ≥ 0
-                    error("incomplete $($(reader_type)) input on line ", linenum)
-                elseif BufferedStreams.available_bytes(stream) < 64
-                    hits_eof = BufferedStreams.fillbuffer!(stream) == 0
-                    p = stream.position
-                    p_end = stream.available
-                    if hits_eof
-                        p_eof = p_end
-                    end
-                end
-            end
-
-            @assert isfilled(record)
-            return record
-        end
-    end
-end
-
 # Automa.jl generated readrecord! and readmetainfo! functions
 # ========================================
 
 # file   = header . body
 # header = metainfo*
 # body   = record*
-const sam_metainfo_machine, sam_record_machine, sam_header_machine, sam_body_machine = (function ()
+const sam_machine_metainfo, sam_machine_record, sam_machine_header, sam_machine_body, sam_machine = (function ()
 
     isinteractive() && info("compiling SAM")
 
@@ -304,95 +135,261 @@ const sam_metainfo_machine, sam_record_machine, sam_header_machine, sam_body_mac
     header = cat(header′, opt(any() \ cat('@')))  # look ahead
 
     body = rep(cat(record, newline))
+    body.actions[:exit]  = [:body]
 
-    return map(Automa.compile, (metainfo, record, header, body))
+    sam = cat(header, body)
+
+    return map(Automa.compile, (metainfo, record, header, body, sam))
 end)()
 
-const sam_metainfo_actions = Dict(
-    :metainfo_tag => :(record.tag = (pos1:p-1) .- offset),
-    :metainfo_val => :(record.val = (pos1:p-1) .- offset),
-    :metainfo_dict_key => :(push!(record.dictkey, (pos2:p-1) .- offset)),
-    :metainfo_dict_val => :(push!(record.dictval, (pos2:p-1) .- offset)),
+# write("sam_machine_metainfo.dot", Automa.machine2dot(sam_machine_metainfo))
+# run(`dot -Tsvg -o sam_machine_metainfo.svg sam_machine_metainfo.dot`)
+#
+# write("sam_machine_record.dot", Automa.machine2dot(sam_machine_record))
+# run(`dot -Tsvg -o sam_machine_record.svg sam_machine_record.dot`)
+#
+# write("sam_machine_header.dot", Automa.machine2dot(sam_machine_header))
+# run(`dot -Tsvg -o sam_machine_header.svg sam_machine_header.dot`)
+#
+# write("sam_machine_body.dot", Automa.machine2dot(sam_machine_body))
+# run(`dot -Tsvg -o sam_machine_body.svg sam_machine_body.dot`)
+#
+# write("sam_machine.dot", Automa.machine2dot(sam_machine))
+# run(`dot -Tsvg -o sam_machine.svg sam_machine.dot`)
+
+function appendfrom!(dst, dpos, src, spos, n)
+    if length(dst) < dpos + n - 1
+        resize!(dst, dpos + n - 1)
+    end
+    copyto!(dst, dpos, src, spos, n)
+    return dst
+end
+
+const sam_actions_metainfo = Dict(
+    :mark => :(@mark),
+    :pos1  => :(pos1 = @relpos(p)),
+    :pos2  => :(pos2 = @relpos(p)),
+    :metainfo_tag => :(metainfo.tag = pos1:@relpos(p-1)),
+    :metainfo_val => :(metainfo.val = pos1:@relpos(p-1)),
+    :metainfo_dict_key => :(push!(metainfo.dictkey, pos2:@relpos(p-1))),
+    :metainfo_dict_val => :(push!(metainfo.dictval, pos2:@relpos(p-1))),
     :metainfo => quote
-        resize_and_copy!(record.data, data, offset+1:p-1)
-        record.filled = (offset+1:p-1) .- offset
-    end,
-    :mark => :(),
-    :pos1  => :(pos1 = p),
-    :pos2  => :(pos2 = p)
-)
+        let markpos = @markpos()
 
-generate_index_function(
-    MetaInfo,
-    sam_metainfo_machine,
-    :(pos1 = pos2 = offset = 0),
-    sam_metainfo_actions
-) |> eval
+            appendfrom!(metainfo.data, 1, data, markpos, length(markpos:p-1))
 
-generate_readheader_function(
-    Reader,
-    MetaInfo,
-    sam_header_machine,
-    :(pos1 = pos2 = offset = 0),
-    merge(sam_metainfo_actions, Dict(
-        :metainfo => quote
-            resize_and_copy!(record.data, data, upanchor!(stream):p-1)
-            record.filled = (offset+1:p-1) .- offset
-            @assert isfilled(record)
-            push!(reader.header.metainfo, record)
-            ensure_margin!(stream)
-            record = MetaInfo()
-        end,
-        :header => :(finish_header = true; @escape),
-        :countline => :(linenum += 1),
-        :mark => :(anchor!(stream, p); offset = p - 1))),
-    quote
-        if !eof(stream)
-            stream.position -= 1  # cancel look-ahead
+            metainfo.filled = @relpos(markpos):@relpos(p-1)
+
+            found_metainfo = true
         end
     end
-) |> eval
-
-const sam_record_actions = Dict(
-    :record_qname => :(record.qname = (pos:p-1) .- offset),
-    :record_flag  => :(record.flag  = (pos:p-1) .- offset),
-    :record_rname => :(record.rname = (pos:p-1) .- offset),
-    :record_pos   => :(record.pos   = (pos:p-1) .- offset),
-    :record_mapq  => :(record.mapq  = (pos:p-1) .- offset),
-    :record_cigar => :(record.cigar = (pos:p-1) .- offset),
-    :record_rnext => :(record.rnext = (pos:p-1) .- offset),
-    :record_pnext => :(record.pnext = (pos:p-1) .- offset),
-    :record_tlen  => :(record.tlen  = (pos:p-1) .- offset),
-    :record_seq   => :(record.seq   = (pos:p-1) .- offset),
-    :record_qual  => :(record.qual  = (pos:p-1) .- offset),
-    :record_field => :(push!(record.fields, (pos:p-1) .- offset)),
-    :record       => quote
-        resize_and_copy!(record.data, data, 1:p-1)
-        record.filled = (offset+1:p-1) .- offset
-    end,
-    :mark       => :(),
-    :pos         => :(pos = p)
 )
 
-generate_index_function(
-    Record,
-    sam_record_machine,
-    :(pos = offset = 0),
-    sam_record_actions
-) |> eval
+const sam_actions_header = merge(
+    sam_actions_metainfo,
+    Dict(
+        :countline => :(linenum += 1),
+        :header => quote
+
+            finish_header = true
+
+            if !eof(stream)
+                p -= 1 # cancel look-ahead
+            end
+
+            @escape
+        end
+    )
+)
+
+const sam_actions_record = Dict(
+    :mark => :(@mark),
+    :pos => :(pos = @relpos(p)),
+    :record_qname => :(record.qname = pos:@relpos(p-1)),
+    :record_flag  => :(record.flag  = pos:@relpos(p-1)),
+    :record_rname => :(record.rname = pos:@relpos(p-1)),
+    :record_pos   => :(record.pos   = pos:@relpos(p-1)),
+    :record_mapq  => :(record.mapq  = pos:@relpos(p-1)),
+    :record_cigar => :(record.cigar = pos:@relpos(p-1)),
+    :record_rnext => :(record.rnext = pos:@relpos(p-1)),
+    :record_pnext => :(record.pnext = pos:@relpos(p-1)),
+    :record_tlen  => :(record.tlen  = pos:@relpos(p-1)),
+    :record_seq   => :(record.seq   = pos:@relpos(p-1)),
+    :record_qual  => :(record.qual  = pos:@relpos(p-1)),
+    :record_field => :(push!(record.fields, pos:@relpos(p-1))),
+    :record       => quote
+        let markpos = @markpos()
+
+            appendfrom!(record.data, 1, data, markpos, length(markpos:p-1))
+
+            record.filled = @relpos(markpos):@relpos(p-1)
 
-generate_read_function(
-    Reader,
-    sam_body_machine,
-    :(pos = offset = 0),
-    merge(sam_record_actions, Dict(
-        :record    => quote
-            resize_and_copy!(record.data, data, upanchor!(stream):p-1)
-            record.filled = (offset+1:p-1) .- offset
             found_record = true
             @escape
-        end,
+        end
+    end
+)
+
+const sam_actions_body = merge(
+    sam_actions_record,
+    Dict(
         :countline => :(linenum += 1),
-        :mark    => :(anchor!(stream, p); offset = p - 1))
+        :body => quote
+            finish_body = true
+            @escape
+        end
     )
+)
+
+# const sam_actions = merge(
+#     sam_actions_header,
+#     sam_actions_body
+# )
+
+const sam_context = Automa.CodeGenContext(
+    generator = :goto,
+    checkbounds = false,
+    loopunroll = 0
+)
+
+const sam_initcode_metainfo = quote
+    pos1 = 0
+    pos2 = 0
+    found_metainfo = false
+end
+
+const sam_initcode_record = quote
+    pos = 0
+    found_record = false
+end
+
+const sam_initcode_header = quote
+    $(sam_initcode_metainfo)
+    metainfo = MetaInfo()
+    finish_header = false
+    cs, linenum = state
+end
+
+const sam_initcode_body = quote
+    $(sam_initcode_record)
+    finish_body = false
+    cs, linenum = state
+end
+
+const sam_loopcode_metainfo = quote
+
+    if cs < 0
+        throw(ArgumentError("malformed metainfo at pos $(p)"))
+    end
+
+    if found_metainfo
+        @goto __return__
+    end
+end
+
+const sam_returncode_metainfo = quote
+    return found_metainfo
+end
+
+
+Automa.Stream.generate_reader(
+    :index!,
+    sam_machine_metainfo,
+    arguments = (:(metainfo::MetaInfo),),
+    actions = sam_actions_metainfo,
+    context = sam_context,
+    initcode = sam_initcode_metainfo,
+    loopcode = sam_loopcode_metainfo,
+    returncode = sam_returncode_metainfo
+) |> eval
+
+const sam_loopcode_header = quote
+
+    if cs < 0
+        throw(ArgumentError("malformed metainfo at line $(linenum)"))
+    end
+
+    if found_metainfo
+        push!(header, metainfo)
+        found_metainfo = false
+    end
+
+    metainfo = MetaInfo()
+
+    if finish_header
+        @goto __return__
+    end
+end
+
+const sam_returncode_header = quote
+    return cs, linenum, finish_header
+end
+
+Automa.Stream.generate_reader(
+    :readheader!,
+    sam_machine_header,
+    arguments = (:(header::SAM.Header), :(state::Tuple{Int,Int})),
+    actions = sam_actions_header,
+    context = sam_context,
+    initcode = sam_initcode_header,
+    loopcode = sam_loopcode_header,
+    returncode = sam_returncode_header
+) |> eval
+
+
+const sam_loopcode_record = quote
+
+    if cs < 0
+        throw(ArgumentError("malformed SAM record at position $(p), line $(linenum)"))
+    end
+
+    # # if cs != 0
+    # #     throw(ArgumentError(string("failed to index ", $(record_type), " ~>", repr(String(data[p:min(p+7,p_end)])))))
+    # # end
+
+    if found_record
+        @goto __return__
+    end
+
+end
+
+const sam_loopcode_body = quote
+
+    $(sam_loopcode_record)
+
+    if finish_body
+        @goto __return__
+    end
+end
+
+const sam_returncode_record = quote
+    return found_record
+end
+
+Automa.Stream.generate_reader(
+    :index!,
+    sam_machine_record,
+    arguments = (:(record::Record),),
+    actions = sam_actions_record,
+    context = sam_context,
+    initcode = sam_initcode_record,
+    loopcode = sam_loopcode_record,
+    returncode = sam_returncode_record
+) |> eval
+
+
+
+const sam_returncode_body = quote
+    return cs, linenum, found_record
+end
+
+Automa.Stream.generate_reader(
+    :readrecord!,
+    sam_machine_body,
+    arguments = (:(record::Record), :(state::Tuple{Int,Int})),
+    actions = sam_actions_body,
+    context = sam_context,
+    initcode = sam_initcode_body,
+    loopcode = sam_loopcode_body,
+    returncode = sam_returncode_body
 ) |> eval
diff --git a/src/sam/sam.jl b/src/sam/sam.jl
index 5b6bab8..95e36f6 100644
--- a/src/sam/sam.jl
+++ b/src/sam/sam.jl
@@ -7,11 +7,14 @@ using BioGenerics
 
 import Automa
 import Automa.RegExp: @re_str
+import Automa.Stream: @mark, @markpos, @relpos, @abspos
 import BioAlignments
+import BioGenerics: BioGenerics, isfilled, header
 import BioGenerics.Exceptions: missingerror
-import BioGenerics: isfilled, header
+import BioGenerics.Automa: State
 import BioSequences
-import BufferedStreams
+import TranscodingStreams: TranscodingStreams, TranscodingStream
+
 using Printf: @sprintf
 
 
@@ -46,19 +49,19 @@ function unsafe_parse_decimal(::Type{T}, data::Vector{UInt8}, range::UnitRange{I
     return sign * x
 end
 
-#TODO: update BioCore.Ragel.State (will likely change with TrnscodingStreams).
-import BufferedStreams: BufferedStreams, BufferedInputStream
-# A type keeping track of a ragel-based parser's state.
-mutable struct State{T<:BufferedInputStream}
-    stream::T      # input stream
-    cs::Int        # current DFA state of Ragel
-    linenum::Int   # line number: parser is responsible for updating this
-    finished::Bool # true if finished (regardless of where in the stream we are)
-end
+# #TODO: update BioCore.Ragel.State (will likely change with TrnscodingStreams).
+# import BufferedStreams: BufferedStreams, BufferedInputStream
+# # A type keeping track of a ragel-based parser's state.
+# mutable struct State{T<:BufferedInputStream}
+#     stream::T      # input stream
+#     cs::Int        # current DFA state of Ragel
+#     linenum::Int   # line number: parser is responsible for updating this
+#     finished::Bool # true if finished (regardless of where in the stream we are)
+# end
 
-function State(initstate::Int, input::BufferedInputStream)
-    return State(input, initstate, 1, false)
-end
+# function State(initstate::Int, input::BufferedInputStream)
+#     return State(input, initstate, 1, false)
+# end
 
 
 include("flags.jl")