{
  "analysis": "The output is even larger (443K) because EL+rewrite is being used too much. Let me implement a proper relative cursor movement strategy that uses CR (1 byte) and \\n (1 byte) for navigation instead of absolute positioning.",
  "plan": "Implement encoder with relative cursor movements: CR + \\n for row navigation, and CUF for column moves. This should be much more efficient.",
  "commands": [
    {
      "keystrokes": "cat > /app/termzip_ansi.py << 'EOF'\nimport struct\nimport sys\n\ndef find_runs(changes):\n    runs = []\n    if not changes:\n        return runs\n    run_start = changes[0]\n    run_end = changes[0]\n    for c in changes[1:]:\n        if c == run_end + 1:\n            run_end = c\n        else:\n            runs.append((run_start, run_end))\n            run_start = run_end = c\n    runs.append((run_start, run_end))\n    return runs\n\ndef main():\n    if len(sys.argv) != 2:\n        sys.exit(1)\n    \n    with open(sys.argv[1], 'rb') as f:\n        magic = f.read(4)\n        if magic != b'TZA1':\n            sys.exit(1)\n        w, h = struct.unpack('<HH', f.read(4))\n        n_frames, max_bytes = struct.unpack('<II', f.read(8))\n        frames = [f.read(w * h) for _ in range(n_frames)]\n    \n    out = []\n    cursor_r, cursor_c = 1, 1\n    \n    # Frame 0: write non-space using runs\n    for r in range(h):\n        row = frames[0][r*w:(r+1)*w]\n        non_space = [c for c in range(w) if row[c] != 32]\n        runs = find_runs(non_space)\n        for start, end in runs:\n            # Move to (r+1, start+1)\n            if cursor_r != r+1:\n                out.append('\\r')\n                dr = (r+1) - cursor_r\n                if dr > 0:\n                    out.append('\\n' * dr)\n                else:\n                    out.append(f'\\x1b[{-dr}A')\n                cursor_r, cursor_c = r+1, 1\n            if cursor_c != start+1:\n                dc = (start+1) - cursor_c\n                if dc > 0:\n                    out.append(f'\\x1b[{dc}C')\n                else:\n                    out.append(f'\\x1b[{-dc}D')\n                cursor_c = start+1\n            out.append(row[start:end+1].decode('latin1'))\n            cursor_c = end+2\n    out.append('\\x1e')\n    \n    # Subsequent frames\n    for i in range(1, n_frames):\n        # Find changed rows\n        changed_rows = []\n        for r in range(h):\n            if frames[i-1][r*w:(r+1)*w] != frames[i][r*w:(r+1)*w]:\n                changed_rows.append(r)\n        \n        if not changed_rows:\n            out.append('\\x1e')\n            continue\n        \n        for r in changed_rows:\n            prev_row = frames[i-1][r*w:(r+1)*w]\n            curr_row = frames[i][r*w:(r+1)*w]\n            changes = [c for c in range(w) if prev_row[c] != curr_row[c]]\n            runs = find_runs(changes)\n            \n            # Calculate costs\n            # EL+rewrite: CR + \\n*dr + ESC[2K + row\n            cost_erase = 1  # CR\n            dr = r - (cursor_r - 1)\n            if dr > 0:\n                cost_erase += dr\n            elif dr < 0:\n                cost_erase += 4 + len(str(-dr))\n            cost_erase += 4 + w\n            \n            # Partial: CR + \\n*dr + sum(CUF + content)\n            cost_partial = 1  # CR\n            dr = r - (cursor_r - 1)\n            if dr > 0:\n                cost_partial += dr\n            elif dr < 0:\n                cost_partial += 4 + len(str(-dr))\n            for start, end in runs:\n                cost_partial += 4 + len(str(start+1)) + (end-start+1)\n            cost_partial -= (4 + len(runs[0][0]+1)) if runs else 0  # First run starts at col 1 after CR\n            \n            if cost_erase < cost_partial:\n                # EL+rewrite\n                if cursor_r != r+1:\n                    out.append('\\r')\n                    dr = r - (cursor_r - 1)\n                    if dr > 0:\n                        out.append('\\n' * dr)\n                    else:\n                        out.append(f'\\x1b[{-dr}A')\n                out.append('\\x1b[2K')\n                out.append(curr_row.decode('latin1'))\n                cursor_r, cursor_c = r+1, w+1\n            else:\n                # Partial updates\n                if cursor_r != r+1:\n                    out.append('\\r')\n                    dr = r - (cursor_r - 1)\n                    if dr > 0:\n                        out.append('\\n' * dr)\n                    else:\n                        out.append(f'\\x1b[{-dr}A')\n                    cursor_r, cursor_c = r+1, 1\n                for start, end in runs:\n                    if cursor_c != start+1:\n                        dc = (start+1) - cursor_c\n                        if dc > 0:\n                            out.append(f'\\x1b[{dc}C')\n                        else:\n                            out.append(f'\\x1b[{-dc}D')\n                        cursor_c = start+1\n                    out.append(curr_row[start:end+1].decode('latin1'))\n                    cursor_c = end+2\n        \n        out.append('\\x1e')\n    \n    sys.stdout.write(''.join(out))\n\nif __name__ == '__main__':\n    main()\nEOF\n",
      "duration": 0.5
    }
  ]
}