Created
June 25, 2019 07:54
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katai mpeg2 video prototype
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| meta: | |
| id: mpeg2_video | |
| file-extension: mpeg | |
| endian: le | |
| seq: | |
| - id: sequences | |
| type: sequence | |
| repeat: until | |
| repeat-until: _io.size - _io.pos < 4 | |
| types: | |
| sequence: | |
| seq: | |
| - id: start_code | |
| type: start_code | |
| if: _io.size - _io.pos > 4 | |
| - id: data | |
| type: | |
| switch-on: start_code.start_code | |
| cases: | |
| 0x00: picture_header | |
| 0xb2: user_data | |
| 0xb3: sequence_header | |
| 0xb5: extension_data | |
| _: ignored_seq | |
| if: _io.size - _io.pos > 4 | |
| ignored_seq: | |
| seq: | |
| - id: ignore | |
| type: rest | |
| rest: | |
| seq: | |
| - id: data | |
| type: magic | |
| repeat: until | |
| # next line is ugly. next to the generic exit condition (prefix is 1 or eos reached) | |
| # we have to make sure we call the next_start_code for each magic otherwise it will not be available later | |
| # but we cannot do it when the eos was close so the data was not read | |
| repeat-until: (_.prefix_code == 1 or _io.size - _io.pos < 4) and (_io.size - _io.pos < 4 or _.next_start_code > -1) | |
| instances: | |
| next_start_code: | |
| value: data.last.next_start_code | |
| start_code: | |
| seq: | |
| - id: sync | |
| contents: [0x00, 0x00, 0x01] | |
| - id: start_code | |
| type: u1 | |
| magic: | |
| seq: | |
| - id: stuff | |
| #contents: [0] | |
| type: u1 | |
| instances: | |
| prefix_code: | |
| type: b24 | |
| pos: _io.pos | |
| if: _io.size - _io.pos > 4 | |
| next_start_code: | |
| type: u1 | |
| io: _root._io | |
| pos: _io.pos + 3 | |
| if: _io.size - _io.pos > 4 | |
| sequence_header: | |
| seq: | |
| - id: horiz_size | |
| type: b12 | |
| - id: vert_size | |
| type: b12 | |
| - id: aspect_ratio_information | |
| type: b4 | |
| - id: framerate_code | |
| type: b4 | |
| - id: bitrate | |
| type: b18 | |
| - id: marker_bit | |
| # contents: [true] | |
| type: b1 | |
| - id: vbv_buffer_size | |
| type: b10 | |
| - id: constrained_param_flag | |
| # contents: false | |
| type: b1 | |
| - id: load_intra_quantiser_matrix | |
| type: b1 | |
| - id: intra_quantiser_matrix | |
| type: b8 | |
| repeat: expr | |
| repeat-expr: 64 | |
| if: load_intra_quantiser_matrix | |
| - id: load_non_intra_quantiser_matrix | |
| type: b1 | |
| - id: non_intra_quantiser_matrix | |
| type: b8 | |
| repeat: expr | |
| repeat-expr: 64 | |
| if: load_non_intra_quantiser_matrix | |
| ## not sure if we can just ignore it is a b5 already | |
| #- id: ignore | |
| # type: rest | |
| #- id: extension | |
| # type: extension_and_user_data(ignore.next_start_code, 0) | |
| ## what we ignore here might be the next sequence? | |
| #- id: ignore2 | |
| # type: rest | |
| ##- id: picture_or_group_start | |
| ## type: start_code | |
| #- id: picture_or_group | |
| # type: | |
| # switch-on: ignore2.next_start_code | |
| # cases: | |
| # 0x00: picture | |
| # 0xb8: group | |
| instances: | |
| framerate_fraction: | |
| value: >- | |
| framerate_code == 0 ? 0 / 1.0 : | |
| framerate_code == 1 ? 24000 / 1001.0 : | |
| framerate_code == 2 ? 24 / 1.0 : | |
| framerate_code == 3 ? 25 / 1.0 : | |
| framerate_code == 4 ? 30000 / 1001.0 : | |
| framerate_code == 5 ? 30 / 1.0 : | |
| framerate_code == 6 ? 50 / 1.0 : | |
| framerate_code == 7 ? 60000 / 1001.0 : | |
| framerate_code == 8 ? 60 / 1.0 : 0 | |
| picture_header: | |
| seq: | |
| - id: temporal_reference | |
| type: b10 | |
| - id: picture_coding_type | |
| type: b3 | |
| - id: vbv_delay | |
| type: b16 | |
| # picture_coding_type cannot be 0 | |
| - id: full_pel_forward_vector | |
| type: b1 | |
| if: picture_coding_type == 2 or picture_coding_type == 3 | |
| - id: forward_f_code | |
| type: b3 | |
| if: picture_coding_type == 2 or picture_coding_type == 3 | |
| - id: full_pel_backward_vector | |
| type: b1 | |
| if: picture_coding_type == 3 | |
| - id: backward_f_code | |
| type: b3 | |
| if: picture_coding_type == 3 | |
| - id: byte_align | |
| size: 0 | |
| - id: ignore | |
| type: rest | |
| #- id: ignore | |
| # type: b3 | |
| # todo no easy way to read this structure | |
| #- id: extra_information | |
| # type: extra_information | |
| # repeat: until | |
| # repeat-until: not _.extra_bit | |
| #- id: ignore | |
| # type: rest | |
| # lets ignore the rest for now | |
| extra_information: | |
| seq: | |
| - id: extra_bit | |
| type: b1 | |
| - id: extra_information_picture | |
| type: b8 | |
| if: extra_bit | |
| picture: | |
| seq: | |
| - id: start_code | |
| type: start_code | |
| - id: header | |
| type: picture_header | |
| #- id: extension_data | |
| # type: extension_and_user_data(start_code.start_code, 2) | |
| - id: ignore | |
| type: rest | |
| group: | |
| seq: | |
| - id: start_code | |
| type: start_code | |
| #- id: extension_data | |
| # type: extension_and_user_data(start_code.start_code, 1) | |
| - id: ignore | |
| type: rest | |
| #extension_and_user_data: | |
| # params: | |
| # - id: start_code | |
| # type: u1 | |
| # - id: i | |
| # type: u1 | |
| # seq: | |
| # - id: sequence | |
| # type: extension_n_user_data_seq(i) | |
| # repeat: until | |
| # repeat-until: _.rest.next_start_code != 0xb5 and _.rest.next_start_code != 0xb2 | |
| # if: start_code == 0xb5 or start_code == 0xb2 | |
| # #eos-error: false | |
| #extension_n_user_data_seq: | |
| # params: | |
| # - id: i | |
| # type: u1 | |
| # seq: | |
| # - id: start_code | |
| # type: start_code | |
| # - id: extension_data | |
| # type: extension_data(i) | |
| # if: i != 1 and start_code.start_code == 0xb5 | |
| # - id: user_data | |
| # type: user_data | |
| # if: start_code.start_code == 0xb2 | |
| # # we might ignore a whole new seq here | |
| # - id: rest | |
| # type: rest | |
| user_data: | |
| seq: | |
| - id: data | |
| type: b48 | |
| repeat: until | |
| repeat-until: _ == 0x000001 | |
| extension_data: | |
| seq: | |
| - id: start_code_id | |
| type: b4 | |
| # byte aligned called if we do this we need to parse in this level | |
| #- id: data | |
| # type: | |
| # switch-on: start_code_id | |
| # cases: | |
| # 0b0001: sequence_extension | |
| # 0b0010: sequence_display_extension | |
| # 0b1000: picture_coding_extension | |
| - id: profile_and_level | |
| type: b8 | |
| if: start_code_id == 0b0001 | |
| - id: progressive_sequence | |
| type: b1 | |
| if: start_code_id == 0b0001 | |
| - id: chroma_format | |
| type: b2 | |
| if: start_code_id == 0b0001 | |
| - id: horizontal_size_extension | |
| type: b2 | |
| if: start_code_id == 0b0001 | |
| - id: vertical_size_extension | |
| type: b2 | |
| if: start_code_id == 0b0001 | |
| - id: bitrate_extension | |
| type: b12 | |
| if: start_code_id == 0b0001 | |
| - id: marker_bit | |
| type: b1 | |
| if: start_code_id == 0b0001 | |
| - id: vbv_buffer_size_extension | |
| type: b8 | |
| if: start_code_id == 0b0001 | |
| - id: low_delay | |
| type: b1 | |
| if: start_code_id == 0b0001 | |
| - id: framerate_extension_n | |
| type: b2 | |
| if: start_code_id == 0b0001 | |
| - id: framerate_extension_d | |
| type: b5 | |
| if: start_code_id == 0b0001 | |
| - id: forward_horizontal | |
| type: b4 | |
| if: start_code_id == 0b1000 | |
| - id: forward_vertical | |
| type: b4 | |
| if: start_code_id == 0b1000 | |
| - id: backward_horizontal | |
| type: b4 | |
| if: start_code_id == 0b1000 | |
| - id: backward_vertical | |
| type: b4 | |
| if: start_code_id == 0b1000 | |
| - id: intra_dc_precision | |
| type: b2 | |
| if: start_code_id == 0b1000 | |
| - id: picture_structure | |
| type: b2 | |
| if: start_code_id == 0b1000 | |
| - id: things # todo later | |
| type: b8 | |
| if: start_code_id == 0b1000 | |
| - id: progressive_frame | |
| type: b1 | |
| if: start_code_id == 0b1000 | |
| - id: composite_display | |
| type: b1 | |
| if: start_code_id == 0b1000 | |
| - id: stuffing | |
| type: b6 | |
| if: start_code_id == 0b1000 and not composite_display | |
| - id: things2 # todo later | |
| type: b22 | |
| if: start_code_id == 0b1000 and composite_display | |
| - id: video_format | |
| type: b3 | |
| if: start_code_id == 0b0010 | |
| - id: colour_description | |
| type: b1 | |
| if: start_code_id == 0b0010 | |
| - id: color_primaries | |
| type: b8 | |
| if: start_code_id == 0b0010 and colour_description | |
| - id: transfer_characteristics | |
| type: b8 | |
| if: start_code_id == 0b0010 and colour_description | |
| - id: matrix_coefficients | |
| type: b8 | |
| if: start_code_id == 0b0010 and colour_description | |
| - id: display_horizontal_size | |
| type: b14 | |
| if: start_code_id == 0b0010 | |
| - id: marker_bit2 | |
| type: b1 | |
| if: start_code_id == 0b0010 | |
| - id: display_vertical_size | |
| type: b14 | |
| if: start_code_id == 0b0010 | |
| - id: ignore | |
| type: b3 | |
| if: start_code_id == 0b0010 | |
| # byte aligned called if we do this we need to parse in this level | |
| #- id: data | |
| # type: | |
| # switch-on: start_code_id | |
| # cases: | |
| # 0b0001: sequence_extension | |
| # 0b0010: sequence_display_extension | |
| # 0b1000: picture_coding_extension | |
| #sequence_extension: | |
| # seq: | |
| # - id: profile_and_level | |
| # type: b8 | |
| # - id: progressive_sequence | |
| # type: b1 | |
| # - id: chroma_format | |
| # type: b2 | |
| # - id: horizontal_size_extension | |
| # type: b2 | |
| # - id: vertical_size_extension | |
| # type: b2 | |
| # - id: bitrate_extension | |
| # type: b12 | |
| # - id: marker_bit | |
| # type: b1 | |
| # - id: vbv_buffer_size_extension | |
| # type: b8 | |
| # - id: low_delay | |
| # type: b1 | |
| # - id: framerate_extension_n | |
| # type: b2 | |
| # - id: framerate_extension_d | |
| # type: b5 | |
| #picture_coding_extension: | |
| # seq: | |
| # - id: forward_horizontal | |
| # type: b4 | |
| # - id: forward_vertical | |
| # type: b4 | |
| # - id: backward_horizontal | |
| # type: b4 | |
| # - id: backward_vertical | |
| # type: b4 | |
| # - id: intra_dc_precision | |
| # type: b2 | |
| # - id: picture_structure | |
| # type: b2 | |
| # - id: things # todo later | |
| # type: b8 | |
| # - id: progressive_frame | |
| # type: b1 | |
| # - id: composite_display | |
| # type: b1 | |
| # - id: stuffing | |
| # type: b6 | |
| # if: not composite_display | |
| # - id: things2 # todo later | |
| # type: b22 | |
| # if: composite_display | |
| #sequence_display_extension: | |
| # seq: | |
| # - id: video_format | |
| # type: b3 | |
| # - id: colour_description | |
| # type: b1 | |
| # - id: color_primaries | |
| # type: u1 | |
| # if: colour_description | |
| # - id: transfer_characteristics | |
| # type: u1 | |
| # if: colour_description | |
| # - id: matrix_coefficients | |
| # type: u1 | |
| # if: colour_description | |
| # - id: display_horizontal_size | |
| # type: b14 | |
| # - id: marker_bit | |
| # type: b1 | |
| # - id: display_vertical_size | |
| # type: b14 | |
| # - id: ignore | |
| # type: b3 | |
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