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@akiyan
akiyan / H40_FULL_JOURNEY.md
Created July 12, 2026 00:12
SEGA-CD full-screen H40 FMV: the journey to a clean full-length playback, and a field method for reasoning without an advisor (EN + JA)

The Journey to a Full-Screen H40 Sega CD FMV

How the full-screen H40 (320×224, 40×28 = 1120 tiles) machi (街) ending was made to stream from disc and play back cleanly — video and audio — with no resolution or audio quality lost.

Final result: S(slip)=0 for the whole movie, steady 15 fps, clean and synced audio, frame 0 a complete load. Build 20260711.e8.p3https://youtu.be/5C6t5pvUo-Y (unlisted).

@akiyan
akiyan / playback_timeline.md
Last active July 13, 2026 02:24
SEGA-CD Tile Texture Reuse Codec — hardware playback timeline (dual-68000 execution & sync)

SEGA-CD Tile Texture Reuse Codec — 実機再生タイムライン(68000 二基)

SEGA-CD(メガCD)の 2 つの 68000 CPU が、実機で MOVIE.DAT ストリームを再生する とき 実際に何を実行し、どう同期し、どのメモリをどれだけ使うか を実行時の視点で まとめたもの。対象は Tile Texture Reuse Codec のプレイヤー boot/movieplay_sp.s(Sub CPU)と boot/movieplay_ip.s(Main CPU)。 メモリ数値は H40フル(320×224 / 40×28=1120セル / 15fps)の実測ビルドに基づく。

この設計は、3 つの厳しいハード制約を 同時に 満たすために存在する:

@akiyan
akiyan / README.md
Last active July 23, 2026 00:54
SEGA-CD FMV codec timeline: Sonic Jam H40/30 single observed-reserve pass 1 (Coa avg 311.0)
@akiyan
akiyan / README.md
Created July 23, 2026 00:52
SEGA-CD FMV codec timeline: Sonic Jam H40/30 exact-late run accounting, cold cap 185 unchanged
@akiyan
akiyan / BadApple_H40_320x224_adpcm22_exact_late_run_timeline.png
Created July 23, 2026 01:02
SEGA-CD FMV codec timeline: Bad Apple H40/30 exact-late run accounting, cold cap 185 unchanged
BadApple_H40_320x224_adpcm22_exact_late_run_timeline.png
@akiyan
akiyan / BadApple_H40_320x224_adpcm22_issue42_e91_timeline.png
Created July 23, 2026 02:46
SEGA-CD FMV codec timeline: Bad Apple H40 e91 distance-weighted aging
BadApple_H40_320x224_adpcm22_issue42_e91_timeline.png
@akiyan
akiyan / BadApple_H40_320x224_adpcm22_issue42_e90_baseline_timeline.png
Created July 23, 2026 02:49
SEGA-CD FMV codec timeline: Bad Apple H40 e90 fixed-frame aging baseline
BadApple_H40_320x224_adpcm22_issue42_e90_baseline_timeline.png
@akiyan
akiyan / BadApple_H40_320x224_adpcm22_issue41_cold180_e92_timeline.png
Created July 23, 2026 03:24
SEGA-CD FMV codec timeline: Bad Apple H40 cold180, Issue #41, e92/p80 TTRC v14
BadApple_H40_320x224_adpcm22_issue41_cold180_e92_timeline.png
@akiyan
akiyan / 20260723-035628-596968_sonic-jam-op-h40_d976b5a1a5_e92_timeline.png
Last active July 23, 2026 04:06
Sonic Jam OP H40 320x224 30fps cold cap 180 e92 codec timeline
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@akiyan
akiyan / 20260723-044630-768636_machi-op-h40_d1bb740743_e92_timeline.png
Created July 23, 2026 04:47
Machi OP H40 320x224 15fps cold cap 400 baseline timeline
20260723-044630-768636_machi-op-h40_d1bb740743_e92_timeline.png