diff options
| -rw-r--r-- | lib/pleroma/helpers/qt_fast_start.ex | 115 |
1 files changed, 57 insertions, 58 deletions
diff --git a/lib/pleroma/helpers/qt_fast_start.ex b/lib/pleroma/helpers/qt_fast_start.ex index 694b583b9..8cba06e54 100644 --- a/lib/pleroma/helpers/qt_fast_start.ex +++ b/lib/pleroma/helpers/qt_fast_start.ex @@ -13,10 +13,11 @@ defmodule Pleroma.Helpers.QtFastStart do # ISO/IEC 14496-12:2015, ISO/IEC 15444-12:2015 # Paracetamol - def fix(binary = <<0x00, 0x00, 0x00, _, 0x66, 0x74, 0x79, 0x70, _::binary>>) do - index = fix(binary, binary, 0, []) + def fix(binary = <<0x00, 0x00, 0x00, _, 0x66, 0x74, 0x79, 0x70, _::bits>>) do + index = fix(binary, 0, nil, nil, []) case index do + :abort -> binary [{"ftyp", _, _, _, _}, {"mdat", _, _, _, _} | _] -> faststart(index) [{"ftyp", _, _, _, _}, {"free", _, _, _, _}, {"mdat", _, _, _, _} | _] -> faststart(index) _ -> binary @@ -27,37 +28,32 @@ defmodule Pleroma.Helpers.QtFastStart do binary end - defp fix(<<>>, _bin, _pos, acc) do - :lists.reverse(acc) + # MOOV have been seen before MDAT- abort + defp fix(<<_::bits>>, _, true, false, _) do + :abort end defp fix( - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), rest::binary>>, - bin, + <<size::integer-big-size(32), fourcc::bits-size(32), rest::bits>>, pos, + got_moov, + got_mdat, acc ) do - if fourcc == "mdat" && size == 0 do - # mdat with 0 size means "seek to the end" -- also, in that case the file is probably OK. - acc = [ - {fourcc, pos, byte_size(bin) - pos, byte_size(bin) - pos, - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), rest::binary>>} - | acc - ] - - fix(<<>>, bin, byte_size(bin), acc) - else - full_size = size - 8 - <<data::binary-size(full_size), rest::binary>> = rest - - acc = [ - {fourcc, pos, pos + size, size, - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), data::binary>>} - | acc - ] - - fix(rest, bin, pos + size, acc) - end + full_size = (size - 8) * 8 + <<data::bits-size(full_size), rest::bits>> = rest + + acc = [ + {fourcc, pos, pos + size, size, + <<size::integer-big-size(32), fourcc::bits-size(32), data::bits>>} + | acc + ] + + fix(rest, pos + size, got_moov || fourcc == "moov", got_mdat || fourcc == "mdat", acc) + end + + defp fix(<<>>, _pos, _, _, acc) do + :lists.reverse(acc) end defp faststart(index) do @@ -72,60 +68,63 @@ defmodule Pleroma.Helpers.QtFastStart do {{_moov, _, _, moov_size, moov}, index} = List.keytake(index, "moov", 0) offset = -free_size + moov_size - rest = for {_, _, _, _, data} <- index, do: data, into: <<>> - <<moov_head::binary-size(8), moov_data::binary>> = moov - new_moov = fix_moov(moov_data, offset) - <<ftyp::binary, moov_head::binary, new_moov::binary, rest::binary>> - end - - defp fix_moov(moov, offset) do - fix_moov(moov, offset, <<>>) + rest = for {_, _, _, _, data} <- index, do: data, into: [] + <<moov_head::bits-size(64), moov_data::bits>> = moov + [ftyp, moov_head, fix_moov(moov_data, offset, []), rest] end - defp fix_moov(<<>>, _, acc), do: acc - defp fix_moov( - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), rest::binary>>, + <<size::integer-big-size(32), fourcc::bits-size(32), rest::bits>>, offset, acc ) do - full_size = size - 8 - <<data::binary-size(full_size), rest::binary>> = rest + full_size = (size - 8) * 8 + <<data::bits-size(full_size), rest::bits>> = rest data = cond do fourcc in ["trak", "mdia", "minf", "stbl"] -> # Theses contains sto or co64 part - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), - fix_moov(data, offset, <<>>)::binary>> + [<<size::integer-big-size(32), fourcc::bits-size(32)>>, fix_moov(data, offset, [])] fourcc in ["stco", "co64"] -> # fix the damn thing - <<version::integer-big-size(4)-unit(8), count::integer-big-size(4)-unit(8), - rest::binary>> = data + <<version::integer-big-size(32), count::integer-big-size(32), rest::bits>> = data entry_size = case fourcc do - "stco" -> 4 - "co64" -> 8 + "stco" -> 32 + "co64" -> 64 end - {_, result} = - Enum.reduce(1..count, {rest, <<>>}, fn _, - {<<pos::integer-big-size(entry_size)-unit(8), - rest::binary>>, acc} -> - {rest, <<acc::binary, pos + offset::integer-big-size(entry_size)-unit(8)>>} - end) - - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), - version::integer-big-size(4)-unit(8), count::integer-big-size(4)-unit(8), - result::binary>> + [ + <<size::integer-big-size(32), fourcc::bits-size(32), version::integer-big-size(32), + count::integer-big-size(32)>>, + rewrite_entries(entry_size, offset, rest, []) + ] true -> - <<size::integer-big-size(4)-unit(8), fourcc::binary-size(4), data::binary>> + [<<size::integer-big-size(32), fourcc::bits-size(32)>>, data] end - acc = <<acc::binary, data::binary>> + acc = [acc | data] fix_moov(rest, offset, acc) end + + defp fix_moov(<<>>, _, acc), do: acc + + for size <- [32, 64] do + defp rewrite_entries( + unquote(size), + offset, + <<pos::integer-big-size(unquote(size)), rest::bits>>, + acc + ) do + rewrite_entries(unquote(size), offset, rest, [ + acc | <<pos + offset::integer-big-size(unquote(size))>> + ]) + end + end + + defp rewrite_entries(_, _, <<>>, acc), do: acc end |