Packages
membrane_mpeg_ts_plugin
2.3.15
2.4.9
2.4.8
2.4.7
2.4.6
2.4.5
2.4.4
2.4.3
2.4.2
2.4.1
2.4.0
2.3.18
2.3.17
2.3.16
2.3.15
2.3.14
2.3.12
2.3.11
2.3.10
2.3.9
2.3.8
2.3.7
2.3.6
2.3.5
2.3.4
2.3.3
2.3.2
2.3.1
2.3.0
2.2.1
2.2.0
2.1.5
2.1.4
2.1.3
2.1.2
2.1.1
2.1.0
2.0.2
2.0.1
2.0.0
1.3.4
1.3.3
1.3.2
1.3.1
1.3.0
1.2.5
1.2.4
1.2.3
1.2.2
1.2.1
1.2.0
1.1.0
1.0.3
1.0.2
1.0.1
1.0.0
MPEG-TS Demuxer that implements the Membrane.Filter behaviour.
Current section
Files
Jump to
Current section
Files
lib/membrane/mpeg/ts/opus_payload.ex
defmodule Membrane.MPEG.TS.OpusPayload do
@moduledoc """
Packetizes and depacketizes Opus for MPEG-TS payloads.
"""
import Bitwise
@spec packetize(binary(), keyword()) :: binary()
def packetize(payload, opts \\ []) when is_binary(payload) do
trim_start = Keyword.get(opts, :trim_start, 0)
trim_end = Keyword.get(opts, :trim_end, 0)
flags =
0xE0
|> maybe_set_flag(trim_start > 0, 0x10)
|> maybe_set_flag(trim_end > 0, 0x08)
header = [
0x7F,
flags,
encode_length(byte_size(payload))
]
header =
header
|> maybe_add_trim(trim_start)
|> maybe_add_trim(trim_end)
IO.iodata_to_binary([header, payload])
end
@spec depacketize(binary()) :: {:ok, binary()} | {:error, atom()}
def depacketize(<<0x7F, flags, rest::binary>>) do
with {:ok, len, rest_after_len} <- parse_length(rest),
{:ok, rest_after_trim} <- parse_trim(flags, rest_after_len),
true <- byte_size(rest_after_trim) >= len do
{:ok, binary_part(rest_after_trim, 0, len)}
else
{:error, reason} -> {:error, reason}
false -> {:error, :payload_too_short}
_ -> {:error, :invalid_header}
end
end
def depacketize(_payload), do: {:error, :missing_header}
defp maybe_set_flag(flags, true, mask), do: flags ||| mask
defp maybe_set_flag(flags, false, _mask), do: flags
defp maybe_add_trim(header, 0), do: header
defp maybe_add_trim(header, value) when value > 0 and value <= 0xFFFF do
[header, <<value::unsigned-big-16>>]
end
defp encode_length(size) do
encode_length_bytes(size, [])
end
defp encode_length_bytes(size, acc) when size >= 0 do
len = min(size, 255)
next_size = size - 255
acc = [acc, len]
if next_size >= 0 do
encode_length_bytes(next_size, acc)
else
acc
end
end
defp parse_length(data) do
parse_length_bytes(data, 0)
end
defp parse_length_bytes(<<>>, _acc), do: {:error, :length_eof}
defp parse_length_bytes(<<len, rest::binary>>, acc) do
acc = acc + len
if len < 255 do
{:ok, acc, rest}
else
parse_length_bytes(rest, acc)
end
end
defp parse_trim(flags, rest) do
with {:ok, rest} <- maybe_drop_trim(rest, flags, 0x10),
{:ok, rest} <- maybe_drop_trim(rest, flags, 0x08) do
{:ok, rest}
end
end
defp maybe_drop_trim(rest, flags, mask) do
if (flags &&& mask) != 0 do
drop_bytes(rest, 2)
else
{:ok, rest}
end
end
defp drop_bytes(rest, count) do
if byte_size(rest) < count do
{:error, :trim_eof}
else
{:ok, binary_part(rest, count, byte_size(rest) - count)}
end
end
end